test(memory): let the musl test fake os.confstr on Windows (#523)

The portability run on main fails since #523: Windows has no
os.confstr, so patching it without create=True raises before the test
runs.

.github/workflows/portability.yml

@@ -1,9 +1,9 @@
-name: Windows and macOS
+name: Windows
 
 permissions:
   contents: read
 
-# Non-blocking portability runs (#420): never on pull requests or in the merge queue, and no context
+# Non-blocking Windows runs (#420; macOS dropped from CI in #571): never on pull requests or in the merge queue, and no context
 # here is a required check. A red run is fixed at its cause before the workspace cutover (#334).
 on:
   push:
@@ -25,10 +25,7 @@ env:
 # run counts (tests/vendor/ci-workflow.test.mjs recomputes it, #493).
 # Measured 2026-10-29 on main runs 40935337099 (dd247e3), 40938407252 (dd247e3), 40941240624 (dd247e3):
 #   slowest leg: 7m24s (py3.12 windows) / 7m31s (py3.13 windows) / 7m32s (py3.14 windows) -> 15 min
-#     (windows 4m56s-7m32s, macos 4m39s-6m14s)
-#   native-trash (#499) has no green main runs yet: its probe, run 40949370943 (2026-10-29), took
-#     about 1 minute per macOS leg, so ceil(1.5 x 2) + 3 gives it 6 minutes (step 4). Recalibrate
-#     after three green runs.
+#     (windows 4m56s-7m32s)
 #   native-trash-linux (#543) has no green main runs yet: it installs the dev requirements and runs
 #     one test module, about 1 minute by the same estimate, so ceil(1.5 x 2) + 3 gives it 6 minutes.
 #     Recalibrate after three green runs.
@@ -40,7 +37,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [windows-latest, macos-latest]
+        os: [windows-latest]
         python-version: ["3.12", "3.13", "3.14"]
 
     steps:
@@ -60,7 +57,7 @@ jobs:
 
       # The runner's TEMP is on C:, the OS disk, where a flush took about 6 ms
       # and a test database's create-to-delete about 111 ms; on the D: work
-      # disk the same took 0.5 ms and 23 ms (macOS: 19 ms). Tests write their
+      # disk the same took 0.5 ms and 23 ms. Tests write their
       # databases under TEMP, so it moves to a folder on D: (measured in #487,
       # run 40915866444). The runner's TEMP was an 8.3 short name
       # (C:\Users\RUNNER~1\...), so the new one is spelled by its short name too
@@ -83,31 +80,6 @@ jobs:
           PM_TEST_SLOWEST: "40"
         run: python -m tests.run_suite -v
 
-  # The real Trash on both macOS CPUs (#499 design §10.2). It runs apart from the suite, so a red
-  # suite never skips the native proof.
-  native-trash:
-    name: native trash on ${{ matrix.os }}
-    runs-on: ${{ matrix.os }}
-    timeout-minutes: 6
-    strategy:
-      fail-fast: false
-      matrix:
-        os: [macos-latest, macos-15-intel]
-
-    steps:
-      - uses: actions/checkout@v7
-
-      - name: Set up Python
-        uses: actions/setup-python@v7
-        with:
-          python-version: "3.12"
-
-      - name: Native trash proof
-        timeout-minutes: 4
-        env:
-          PM_NATIVE_TRASH: macos
-        run: python -m unittest tests.test_trash_macos_native tests.test_trash_macos -v
-
   # The same tests as the fake mount table, on a real ext4 mount used as the output root (#543). A
   # runner can mount with sudo; the tests run as the normal user, so owner and mode checks are real.
   native-trash-linux:

.github/workflows/test.yml

@@ -28,7 +28,7 @@ env:
 #   py matrix, slowest py3.10 on windows-latest: 12m43s / 15m54s / 14m53s -> 27 min
 #     (ubuntu 5m27s-6m27s, macos 6m14s-8m30s, windows 11m42s-15m54s)
 #     3.10 and 3.11 left the matrix and 3.14 joined it in #356; re-measure after three green main runs.
-#     Windows and macOS moved to portability.yml (#420), which has its own measured limit (#493);
+#     Windows moved to portability.yml (#420; macOS left CI in #571), which has its own measured limit (#493);
 #     this Linux-only matrix keeps 27 minutes until it is re-measured.
 #   real ComfyUI compatibility: 13m32s / 8m55s / 11m46s -> 24 min
 #   coverage gate (85%): 7m26s / 7m22s / 7m54s -> 15 min
@@ -39,7 +39,7 @@ env:
 # Pull requests run a fast subset (#420): Python 3.12 on ubuntu-latest, coverage, lint and frontend
 # modules. The merge queue (merge_group), pushes to main and manual runs add Python 3.13 and 3.14 on
 # Linux and the real ComfyUI job. "all tests" is the required gate that holds the queue to that set.
-# Windows and macOS run in portability.yml (push to main, nightly, on demand) and never gate a merge.
+# Windows runs in portability.yml (push to main, nightly, on demand) and never gate a merge.
 jobs:
   test:
     name: py${{ matrix.python-version }} on ${{ matrix.os }}

.github/workflows/viewerjs-check.yml

@@ -41,9 +41,13 @@ concurrency:
 # 7.3m-12.2m), because --shard splits by test count and the slow concept specs sort into shard 1. The page
 # workflows now run in three shards per browser with the limits unchanged; the per-shard times are
 # re-measured after three green main runs.
+# #563: coverage shards reached their 18-minute step limit three times on 2026-10-31 with no failing
+# test (PR #560 shard 2/3: 814 passed in 17.9m; queue run 41206495451 shard 1/3: 827 passed; PR #564
+# shard 2/3 twice), against recent green shards of 11m-17m. Coverage now runs in four shards with the
+# limits unchanged; the per-shard times are re-measured after three green main runs.
 jobs:
   frontend-coverage:
-    name: frontend coverage (shard ${{ matrix.shard }}/3)
+    name: frontend coverage (shard ${{ matrix.shard }}/4)
     runs-on: ubuntu-latest
     # Layout comparisons depend on the fonts each browser falls back to, so browser jobs run in the
     # same pinned Playwright image as local runs (tag = @playwright/test in tools/vendor/package-lock.json;
@@ -59,7 +63,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        shard: [1, 2, 3]
+        shard: [1, 2, 3, 4]
     steps:
       - uses: actions/checkout@v7
       # The image's own Python 3.12 and Node 24: setup-python/setup-node install the runner's toolcache
@@ -88,13 +92,13 @@ jobs:
       - run: npm ci --prefix tools/vendor --ignore-scripts
       # Shard 1 also runs the node units and the viewer suite, so the vendor pins and the tooling tests
       # run on the lightest shard instead.
-      - if: matrix.shard == 3
+      - if: matrix.shard == 4
         run: npm run --prefix tools/vendor check
-      - if: matrix.shard == 3
+      - if: matrix.shard == 4
         run: npm run --prefix tools/vendor test
-      - name: Page workflows with coverage, shard ${{ matrix.shard }}/3
+      - name: Page workflows with coverage, shard ${{ matrix.shard }}/4
         timeout-minutes: 18
-        run: npm run --prefix tools/vendor test:coverage:shard -- ${{ matrix.shard }}/3
+        run: npm run --prefix tools/vendor test:coverage:shard -- ${{ matrix.shard }}/4
       - name: Upload raw coverage
         uses: actions/upload-artifact@v7
         with:
@@ -136,13 +140,13 @@ jobs:
         with:
           pattern: coverage-raw-*
           path: ${{ runner.temp }}/coverage-raw
-      # coverage:merge only checks that raw files exist; merging two of three shards would report
+      # coverage:merge only checks that raw files exist; merging three of four shards would report
       # partial coverage, so a missing or empty shard artifact fails here.
       - name: Verify every shard's raw coverage arrived
         shell: bash
         env:
           STAGED_RAW: ${{ runner.temp }}/coverage-raw
-          EXPECTED_SHARDS: 3
+          EXPECTED_SHARDS: 4
         run: |
           found=0
           for shard in $(seq 1 "$EXPECTED_SHARDS"); do

README.md

@@ -167,6 +167,8 @@ Searches your library by text, category, tags and minimum rating, then outputs t
 
 ![Prompt Search List node producing three images](assets/readme/node-search.webp)
 
+To get the images of a Search List batch linked to their prompts, wire the Search List output into a Prompt Manager Text node, not straight into CLIP Text Encode. Wired straight in, the images stay unlinked: the search text is never saved as a prompt.
+
 ## Install
 
 **Requirements:** ComfyUI and Python 3.12 or newer. `watchdog` and `Pillow` are the only dependencies of their own; the rest comes with ComfyUI.
@@ -236,12 +238,12 @@ The documentation for those pages is in [README-legacy.md](README-legacy.md).
 
 | Layer | What runs |
 | --- | --- |
-| Python | Over 200 test files on Linux, Windows and macOS with Python 3.12 to 3.14, with an 85% coverage gate |
+| Python | Over 200 test files on Linux and Windows with Python 3.12 to 3.14, with an 85% coverage gate |
 | Frontend | About 100 unit test files, with coverage floors per file |
 | Browser | Over 60 Playwright spec files in Chromium, Firefox, WebKit and touch emulation |
 | Real ComfyUI | A pinned CPU ComfyUI, started in Classic and Nodes 2.0, running real workflows |
 
-Linux runs on every pull request and in the merge queue. Windows and macOS run on every push to main and nightly. To run the tests yourself, see [TESTING.md](TESTING.md).
+Linux runs on every pull request and in the merge queue. Windows runs on every push to main and nightly. macOS is not tested; it should work, but support is best-effort. To run the tests yourself, see [TESTING.md](TESTING.md).
 
 ## License
 

TESTING.md

@@ -74,14 +74,14 @@ V8 files it writes under `coverage/js/raw`:
 
 ```sh
 PM_TEST_WORKERS=8 npm run --prefix tools/vendor test:coverage            # whole run, one report
-npm run --prefix tools/vendor test:coverage:shard -- 1/3                 # node units, viewer suite, workflows 1/3
-npm run --prefix tools/vendor test:coverage:shard -- 2/3                 # workflows 2/3 (likewise 3/3)
+npm run --prefix tools/vendor test:coverage:shard -- 1/4                 # node units, viewer suite, workflows 1/4
+npm run --prefix tools/vendor test:coverage:shard -- 2/4                 # workflows 2/4 (likewise 3/4, 4/4)
 npm run --prefix tools/vendor coverage:merge                             # report and baseline check of every raw file
 npm run --prefix tools/vendor test:workflows -- --project webkit --shard 2/2
 ```
 
 `coverage:merge` refuses an empty raw directory; it does not count shards, so run
-every shard first (CI's merge job checks all three arrived). Measured on a 32-CPU
+every shard first (CI's merge job checks all four arrived). Measured on a 32-CPU
 machine in the pinned image (2026-10-21): `test:coverage` takes about 5 minutes
 with 8 workers and 24 minutes with 1; all four projects, 8 workers, each test 3
 times (6132 tests), 24 minutes. A CI-sized run (`docker run --cpus=4`,
@@ -189,14 +189,14 @@ check, so run it before pushing a new or deleted frontend file instead of
 waiting for the `frontend coverage` jobs.
 
 The `viewerjs` check runs on every PR, including backend-only changes. It is an
-aggregate job. It requires the three `frontend coverage (shard N/3)` jobs and
+aggregate job. It requires the four `frontend coverage (shard N/4)` jobs and
 `frontend coverage (merge)` to succeed on every event. The four
 `page workflows (firefox|webkit, shard N/2)` jobs run only in the merge queue,
 on `main` and on `workflow_dispatch` (see "Pull requests and the merge queue").
 `viewerjs` requires them to be skipped on a pull request and to succeed
 everywhere else. Any other failed, cancelled or skipped job fails it. Every browser job runs with `PM_TEST_WORKERS: 3` (the public
-runners have 4 vCPUs). Each coverage shard runs `test:coverage:shard -- N/3`
-(shard 1 also runs the node units and the viewer suite, shard 3 the vendor pins
+runners have 4 vCPUs). Each coverage shard runs `test:coverage:shard -- N/4`
+(shard 1 also runs the node units and the viewer suite, shard 4 the vendor pins
 and tooling tests) and uploads its raw V8 files as `coverage-raw-N` (kept 3
 days). The merge job downloads them, fails unless all three arrived with raw
 files and without clashing names, then runs `coverage:merge` (report plus
@@ -261,7 +261,7 @@ the process exits non-zero.
   job fails anyway and the dump is what matters.
 - `PM_TEST_SLOWEST=N` (off by default) lists the N slowest tests after the
   summary, each timed from its `start:` line to the next one like the hang
-  limit. The Windows and macOS jobs (`portability.yml`) set it to 40, so every
+  limit. The Windows jobs (`portability.yml`) set it to 40, so every
   run shows where its time went (#487). The list prints only when the run
   ends: a job GitHub cancels or a watchdog exit prints none, so read the
   timestamps between `start:` lines instead.
@@ -327,7 +327,7 @@ Python 3.13/3.14, real ComfyUI and Firefox/WebKit failures first show up in the
 merge queue, on the merge-group commit rather than the
 pushed one. Find that run with `gh run list --event merge_group --workflow test.yml`
 (or `viewerjs-check.yml`) and match its head branch
-(`gh-readonly-queue/main/pr-<N>-...`). Windows and macOS failures show up only
+(`gh-readonly-queue/main/pr-<N>-...`). Windows failures show up only
 after the merge, in `gh run list --workflow portability.yml`.
 
 Start fixing as soon as a failed log shows the cause, but push the fix only after
@@ -345,11 +345,16 @@ and the time left. The steps, in order:
    monitor's callbacks (Needs review recorder, preview queue, Images listing
    listener).
 2. `ImageMonitor.stop_monitoring` works against one 5 s deadline. Closing the
-   image handler joins the image worker; watchdog's `observer.stop()` (not
-   bounded here) and the observer join get what is left, which can be 0 s.
-3. `close_auto_thumbnails(final=True)` stops the preview worker (30 s) and
-   kills ffmpeg.
-4. `PromptTracker.shutdown` stops the prompt cleanup thread (2 s).
+   image handler joins the image worker; watchdog's `observer.stop()` and the
+   observer join get what is left, which can be 0 s. `stop()` joins watchdog's
+   emitters without a limit, so it runs on a daemon thread and is waited for
+   only until the deadline; a later stop waits for that same call (#561).
+3. `close_auto_thumbnails(final=True)` stops the preview worker (30 s),
+   kills ffmpeg and shuts the interactive image pool down.
+4. `shutdown_job_pool` (`utils/parallel.py`) cancels the long-lived job pool's
+   queued items and joins its threads (5 s; part `workers`, only when a job
+   used the pool, #523).
+5. `PromptTracker.shutdown` stops the prompt cleanup thread (2 s).
 
 A failing step, or a second Ctrl+C, is logged with its traceback and does not
 skip the later steps. A clean run logs one INFO line to PromptManager's log:
@@ -361,6 +366,15 @@ stored, with the parts not reached False, and the `atexit` callback is
 removed: the later steps are skipped, no summary line is logged, and a later
 call returns that result and runs nothing.
 
+The observer is started from a short-lived daemon thread, so every thread it
+creates is a daemon (a thread inherits that flag from the thread that creates
+it). watchdog 7 on Windows starts a plain `threading.Thread` per watch for its
+`ReadDirectoryChangesW` reader; created from ComfyUI's main thread it would not
+be a daemon, and the interpreter waits for every such thread before it runs any
+`atexit` callback, so the teardown would never start (#561).
+`tests/test_package_exit.py` runs a child whose observer does both (a plain
+reader thread, a `stop()` that never returns) and requires its exit.
+
 ComfyUI never runs aiohttp's `on_cleanup` hooks, because it never calls
 `runner.cleanup()`. So `atexit` is the live host's path. It runs on Ctrl+C
 (`main.py` catches `KeyboardInterrupt` and returns) and on a normal exit.
@@ -445,12 +459,44 @@ A hot SQLite read that returns many rows aggregates them into one step
 (`json_group_array`) instead of stepping once per row, so it does not wait for
 the GIL once per row while ComfyUI generates (#354, `get_image_link_matches`).
 
+A metadata read never decodes pixels (#523). Pillow's `PngImageFile.text` loads
+every pixel to reach text chunks after IDAT; the scan (`_extract_comfyui_metadata`)
+and the image monitor (`ComfyUIMetadataExtractor.extract_metadata`) read PNG text
+through `utils/png_text.py`, which runs Pillow's own chunk handlers after the
+first IDAT and seeks over pixel data. The legacy `.text` read is the floor:
+`tests/test_png_text.py` compares both readers on every image under
+`tests/fixtures`, a curated corpus (text after IDAT, zTXt, iTXt, split IDAT, bad
+checksums, truncations, oversized text, APNG) and a seeded fuzz, and asserts that
+neither reader decodes pixels by patching `ImageFile.load`. The only reads that
+differ are files whose pixel data is undecodable or cut short: legacy found
+nothing, the walk keeps the text before the pixels. Animated PNGs still use
+`.text`.
+
+Image work runs on PromptManager's own threads (#523). glibc keeps each thread's
+malloc arena at its high-water mark, so image buffers spread over the default
+executor's threads stay resident. Interactive image work (view previews behind their
+gate, workspace card facts, both inspector routes) runs on the API's fixed
+`pm-image` pool (`IMAGE_POOL_SIZE` 3, `_run_image`, `_map_image`; card facts already
+cached answer without a trip; while the gate's 3 preview writes hold every thread, a
+card or inspector read waits for one of them, by design of the merged pool; after the
+package teardown the pool is not recreated and late calls use the default executor). Jobs (scan metadata and file facts, thumbnail and
+convert jobs, the legacy gallery generation, capture previews) run through
+`map_parallel` on one long-lived `pm-worker` pool of Worker threads, reused between
+jobs; a new Worker threads value replaces it (the teardown also joins a replaced pool
+still finishing), and a call made from a job thread runs inline. After a scan, thumbnail or convert job, or the legacy gallery generation,
+`release_free_memory` (`utils/native_memory.py`) calls glibc's `malloc_trim(0)` once;
+it does nothing on Windows, macOS and musl and never raises. No allocator setting
+changes. `tests/test_image_pools.py` asserts the thread of each read and write and the
+trim; `tests/test_utils_parallel.py` the pool's reuse, resize, nesting and shutdown.
+`tools/perf/memory_drive.py` (manual, Linux, never in CI) measures RSS, heap, threads
+and arenas under the #523 load against the disposable browser test server.
+
 The `perf budget` job in `.github/workflows/test.yml` is the reference
 measurement: `ubuntu-latest`, one Python, no coverage, only the wall-clock tests.
 It runs on every push to `main` and on `workflow_dispatch`, never on pull
 requests, because shared-runner timing must not block a merge. Dispatch it on a
 branch to measure before merging.
-Shared Windows and macOS runners do not run them; the structural tests cover
+Shared Windows runners do not run them; the structural tests cover
 portability. Run it locally with
 `PROMPTMANAGER_PERF_BUDGET=1 python -m unittest tests.test_api_workspace_images.TestWorkspaceImages.test_filter_budget`
 and quote the printed p95 in the PR body.
@@ -646,10 +692,10 @@ Before changing paths, SQLite, streams, restore or cleanup:
   ordinary busy timeout; cross-thread handoffs wait on events with generous
   ceilings, never a short wall clock (#242).
 - Run native Windows CI early for these changes. Pull requests and the merge
-  queue run only Linux, so start Windows and macOS on the branch with
+  queue run only Linux, so start Windows on the branch with
   `gh workflow run portability.yml --ref <branch>`.
-  Include a Windows impact and evidence note in the PR. All six Windows/macOS
-  combinations in that run, every Linux leg and every applicable
+  Include a Windows impact and evidence note in the PR. All three Windows
+  legs in that run, every Linux leg and every applicable
   exact-head check must pass before merge. Portable `ntpath`/`PureWindowsPath`
   controls do not establish native filesystem, locking or cleanup success.
 
@@ -664,11 +710,11 @@ what runs:
 | `py3.13 on ubuntu-latest`, `py3.14 on ubuntu-latest` | not created | run |
 | `real ComfyUI compatibility` | skipped | runs |
 | `coverage gate (85%)`, `black and flake8`, `frontend modules`, `bandit (high severity)` | run | run |
-| `frontend coverage (shard N/3)`, `frontend coverage (merge)` (vendor pins and tooling tests on shard 3) | run | run |
+| `frontend coverage (shard N/4)`, `frontend coverage (merge)` (vendor pins and tooling tests on shard 4) | run | run |
 | `page workflows (firefox\|webkit, shard N/2)` | skipped | run |
 | `all tests`, `viewerjs` (gates) | run | run |
 | `perf budget` | skipped | push and dispatch only (not in the queue) |
-| `py3.12-3.14 on windows-latest/macos-latest` (`portability.yml`) | not run | push to `main`, nightly, `workflow_dispatch` only; never required |
+| `py3.12-3.14 on windows-latest` (`portability.yml`) | not run | push to `main`, nightly, `workflow_dispatch` only; never required |
 
 GitHub has one required set for pull requests and the queue. A job skipped by
 its `if:` reports Success. A dropped matrix leg never reports, so it would stay
@@ -681,8 +727,9 @@ guarantee:
 So a merge group cannot turn green unless all three Linux Python legs, real
 ComfyUI and the four browser shards passed.
 
-Windows and macOS (Python 3.12-3.14) are out of the blocking path for now
-(maintainer, 2026-10-28). They run in `portability.yml` on every push to `main`,
+Windows (Python 3.12-3.14) is out of the blocking path for now
+(maintainer, 2026-10-28). macOS is not tested in CI (maintainer, 2026-10-31, #571);
+its code stays and support is best-effort. They run in `portability.yml` on every push to `main`,
 nightly and on demand, and no context there is required. A red portability run
 is still a failure: fix it at its cause, not by rerunning, and have every one
 green before the workspace cutover (#334). `tests/vendor/ci-workflow.test.mjs` pins the
@@ -1407,6 +1454,8 @@ is shorter than the row it reserves.
 Each Overview card is the count of the page it names: the shell's Library, Images and Tags sidebar counts, one source,
 so a card and its badge cannot differ. `/prompt_manager/stats` is for the legacy page and counts raw rows. A visit re-reads
 the three unless a read is in flight. An unread or failed card shows a dash; Retry re-reads only the failed counts.
+System › Overview's Images metric reads the same shell count (#555), so it, the Overview card and the Images badge show
+one number; its Statistics dialog labels the legacy row counts as "Database records".
 Tests: `tests/js/workspace-state.test.js`, `tests/browser/workspace.spec.mjs`, `tests/comfyui/workspace.spec.mjs`.
 
 ### Images page controls and recorded deviations (#249 PR C)
@@ -2549,8 +2598,8 @@ files to the system trash. **No code path unlinks or overwrites a media file.**
   ("Moving files to the Recycle Bin isn't available on Windows: files larger than the bin's
   capacity would be deleted permanently."). Library-only removal works everywhere. Tests use `tests/fake_trash.py`; the
   browser test server installs it, so no test touches a real trash. The native proof,
-  `tests/test_trash_macos_native.py`, runs only with `PM_NATIVE_TRASH=macos` in
-  portability.yml's `native-trash` job (`macos-latest` and `macos-15-intel`): the startup
+  `tests/test_trash_macos_native.py`, runs only with `PM_NATIVE_TRASH=macos` on a Mac, by hand
+  (CI dropped its `native-trash` macOS job in #571; it last passed on `macos-latest` and `macos-15-intel`): the startup
   volume, a name clash, fresh APFS and FAT32 disk images, an image used as an output root,
   a read-only image and an unwritable folder (design and probe:
   `docs/egm/499-macos-trash/`, local).
@@ -3844,8 +3893,8 @@ workspace never asks; previews are a cache the server keeps:
 - `GET /images/serve/thumbnails/<rel>_thumb<ext>` for a missing preview is refused as
   text first (traversal, a backslash, a drive or stream colon, empty or dot segments, so
   `D:/x`, `\\server\share` and a leading `/` never reach a joined path), then admitted
-  on the event loop (`_PreviewGate`): 3 previews are written at once on the API's own
-  `pm-preview` pool (never the default executor), one flight runs per file (the history
+  on the event loop (`_PreviewGate`): 3 previews are written at once on the API's
+  interactive `pm-image` pool (never the default executor; #523), one flight runs per file (the history
   route shares the flight key and the admission), and at most 64 requests wait; one
   more gets its fallback at once without listing a folder. Inside the admission the
   preview maps back to its media file under the same root (exact names, then one folder
@@ -3878,7 +3927,7 @@ workspace never asks; previews are a cache the server keeps:
   `exclusive` job runs (`_auto_thumbnail_blocker`), checked when a write starts (after
   its slot) and again just before its rename.
 - Shutdown is bounded and logged: the worker stops at a file boundary, ffmpeg is
-  killed, an idle worker leaves (the next output starts a fresh one), the view pool
+  killed, an idle worker leaves (the next output starts a fresh one), the image pool
   shuts down, and after the app's cleanup a late monitor event
   starts nothing. A package reload stops the workers the previous import left.
 - Cards and strips load previews only: Images in every layout and size, Library cards,
@@ -4006,7 +4055,11 @@ the per-section hand-off panel, was retired by S12 (#329): every section is nati
   "Save preferences" is `aria-disabled` (opacity .55, `not-allowed`) while clean or
   saving; a setting the last save could not save gets a red outline. CSS under D92.
 - **D93** (Overview): real values. The metrics are the Library's eligible positives
-  and active saved negatives and the indexed `generated_images` rows (Q2). "Database
+  and active saved negatives and the Images count (#555, amending Q2's indexed
+  `generated_images` rows): the shell's Images sidebar count, the Images page's own
+  total, which also lists files no row links, as the concept's `images.length` is
+  both. A visit re-reads it unless a read is in flight; "–" until read or after a
+  failed read. `images.indexed` stays in the API and is not shown. "Database
   integrity" is "Not checked" until a check ran this session, then "N issues" (checks
   that found issues, even beside a check that could not run), "Passed" or "Incomplete".
   The review row is "N ambiguous image links" (the Needs review queue's pending count,
@@ -4044,10 +4097,11 @@ the per-section hand-off panel, was retired by S12 (#329): every section is nati
 - **D96** (Statistics; amended by D153): "Usage statistics" without the sample note: the
   concept's "Runs by category" table without its Avg. rating column (Category / Runs)
   with the real runs of eligible parents per category ("Uncategorized"), then a second
-  table "Library totals" (Total / Count: Prompts, Tags, Images from the legacy
-  statistics; no Rated images). The API still reports `average_rating` and
+  table "Database records" (Total / Count: Prompt records, Tags on prompts, Image
+  records: the raw row counts of the legacy statistics, labelled as rows so they never
+  read as the Library or Images page counts, #555; no Rated images). The API still reports `average_rating` and
   `rated_images`; the workspace does not show them.
-  The Overview row says "Runs by category, with library totals." because
+  The Overview row says "Runs by category, with database record counts." because
   that is what the dialog shows (the concept's own dialog shows only "Runs by
   category"); per-prompt run counts, prompt tags and dated runs are recorded, but no
   table of them exists yet. A failed read toasts "Statistics could not
@@ -4350,6 +4404,23 @@ the per-section hand-off panel, was retired by S12 (#329): every section is nati
   choice. The host's checks still refuse a linked field or a changed workflow, and the
   sender also refuses if the destination's `revision` (node object plus graph version)
   moved since discovery; it is undefined on an older tab, which skips the comparison. A host error reads as a refusal, not "may have applied".
+- **D191** (#542, beyond the concept; maintainer 2026-10-31, Q542-1 A to 5 A): a window with two or more
+  eligible nodes adds a last Destination node option "All N eligible nodes" (`ALL_NODES` in
+  `prompt-sender.mjs`), never selected for you (D173). Eligible is D173's filter; the nodes it leaves out
+  stay counted in the discovery sentence. One window only. Preview stays optional (D175): Preview changes
+  shows one `section.prompt-sender-node` per node, headed "#<id> <title>", in send order (node id,
+  numeric). Apply previews every node first and writes nothing if any refuses ("#<id> <title>: <reason>
+  Nothing was sent."). Then it sends one node after another. Only the first node of a pass taken in that
+  click keeps its ticket; every other node, and every node of a held Preview (host tickets expire after
+  30 s), takes a fresh ticket that is refused unless its Before texts and composition equal the reviewed
+  ones. That fresh preview checks the discovered revision until something has been posted, and not after,
+  since our own write may move the graph version. Refusals are best effort: "Sent to 2 of 3 nodes in
+  <window>. #12 <title>: <host's refusal>."; Apply stays available and a retry sends to every node again
+  (rewriting the same text). A lost reply stops the run, names that node as unknown and lists the nodes
+  not sent. Closing the dialog stops after the current node. The review sections are labelled by their
+  `h4` node heading. Unit tests in `tests/js/prompt-sender.test.js`, a fake three-node host in
+  `tests/browser/prompt-inspector.spec.mjs`, real Classic and Nodes 2.0 widgets in
+  `tests/comfyui/prompt-sender.spec.mjs`.
 - **D106** (Integrations, S10, Q8): the send bridge always asks for the ComfyUI window
   and node, and the nodes always follow ComfyUI's own renderer, so "Default send
   destination" offers only "Ask each time" and "Host compatibility" only "Follow host
@@ -5413,7 +5484,7 @@ list stay unscoped: any row's control proves them.
 | Worker threads | `admin.html:437–445` | S4 Sources | covered | `sources` · slider · "Worker threads" | worker range max is cpu_count (workspace-system-sources.spec.mjs) |
 | LoraManager badge, enable, path, trigger words, CivitAI key, clear key | `admin.html:448–490`; `admin.js:1052–1156` | S10 Integrations | covered | `integrations` · switch · "LoraManager integration" | LoRA rows show detected / enabled / cache-loaded separately (workspace-system-integrations.spec.mjs) |
 | LoRA data import with progress | `admin.html:492–498,517–541`; `admin.js:1157` | S10 Integrations | covered | `integrations` · button · "Review import" | Review import shows replacement, blocked items and network effects with the backup box; Start opens the job (D107) (workspace-system-integrations.spec.mjs) |
-| Statistics | `admin.html:159`; `admin.js:1627` | S2 Overview | covered | `overview` · button · "Explore" | statistics dialog lists runs by category and library totals (workspace-system.spec.mjs) |
+| Statistics | `admin.html:159`; `admin.js:1627` | S2 Overview | covered | `overview` · button · "Explore" | statistics dialog lists runs by category and database record counts (workspace-system.spec.mjs) |
 | Export components JSON `/export` | `admin.html:163`; `admin.js:1607`; `py/api/prompts.py:238` | S9 Backup & export | covered | `backups` · button · "Export all prompts JSON" | Export JSON downloads /library/export; secondary buttons download all prompts (/export) and /pairs/export (D103) (workspace-system-backups.spec.mjs) |
 | Saved pairs export | `py/api/pairs.py:84` | S9 Backup & export | covered | `backups` · button · "Export saved pairs JSON" | Export JSON downloads /library/export; secondary buttons download all prompts (/export) and /pairs/export (D103) (workspace-system-backups.spec.mjs) |
 | Library export | `py/api/library.py:223` | S9 Backup & export | covered | `backups` · button · "Export JSON" | Export JSON downloads /library/export; secondary buttons download all prompts (/export) and /pairs/export (D103) (workspace-system-backups.spec.mjs) |

__init__.py

@@ -92,10 +92,20 @@ try:
     routes = config.routes
     api = PromptManagerAPI()
     api.add_routes(routes)
-    # Temp files of preview writes a crash interrupted (#317), off the
-    # import path: the walk may cover a large thumbnails folder.
+
+    # The thumbnail location's startup check (#320), then the temp files of
+    # preview writes a crash interrupted (#317), off the import path: the
+    # walk may cover a large thumbnails folder.
+    # #320: the configured thumbnail location is in force before any request
+    # (no I/O); the thread below checks it.
+    api.use_preview_location()
+
+    def _preview_startup():
+        api.start_preview_location()
+        api.sweep_thumbnail_temps()
+
     threading.Thread(
-        target=api.sweep_thumbnail_temps,
+        target=_preview_startup,
         name="PromptManagerPreviewTempSweep",
         daemon=True,
     ).start()
@@ -120,6 +130,7 @@ except Exception as e:
         logger = get_logger("prompt_manager.init")
         logger.error(f"Failed to register API routes: {e}")
     except Exception:
+        # logging failed too; a report must never stop the node loading
         pass
 
 # Shared database, set up with the monitoring system below. Stays None when that
@@ -279,11 +290,11 @@ def _teardown_logger():
 
 
 def _stop_background_work():
-    """Stop the image monitor, the preview worker and the prompt cleanup
-    thread against one TEARDOWN_SECONDS deadline, once.
+    """Stop the image monitor, the preview worker, the job worker threads
+    and the prompt cleanup thread against one TEARDOWN_SECONDS deadline, once.
 
-    Returns ``{"monitor", "thumbnails", "tracker"}`` booleans (True: it
-    stopped), leaving out parts that never started. Later calls return a
+    Returns ``{"monitor", "thumbnails", "workers", "tracker"}`` booleans
+    (True: it stopped), leaving out parts that never started. Later calls return a
     copy of the first result. A Ctrl+C inside a step is logged and the
     step is False; one between steps is re-raised after the result (parts
     not reached are False) is stored and the ``atexit`` entry removed.
@@ -297,11 +308,14 @@ def _stop_background_work():
             api,
             _global_prompt_tracker,
         )
+        from .utils import parallel
+
         # A part whose global is set has started; False until its step says
         # otherwise, so an interrupt between steps leaves an honest result.
         started = (
             ("monitor", monitor),
             ("thumbnails", thumbnails),
+            ("workers", parallel.job_pool_started() or None),
             ("tracker", tracker),
         )
         result = {name: False for name, part in started if part is not None}
@@ -344,6 +358,16 @@ def _stop_background_work():
                 result["thumbnails"] = _teardown_step(
                     "the preview worker", close_previews, logger
                 )
+            if "workers" in result:
+
+                def stop_workers():
+                    from .utils.parallel import JOB_POOL_JOIN_SECONDS
+
+                    return parallel.shutdown_job_pool(left(JOB_POOL_JOIN_SECONDS))
+
+                result["workers"] = _teardown_step(
+                    "the job worker threads", stop_workers, logger
+                )
             if tracker is not None:
 
                 def stop_tracker():
@@ -411,6 +435,7 @@ except Exception as e:
             f"Failed to register the exit signal: {e}"
         )
     except Exception:
+        # logging failed too; a report must never stop the node loading
         pass
 
 try:
@@ -428,16 +453,14 @@ except Exception as e:
             f"Failed to register the background work teardown: {e}"
         )
     except Exception:
+        # logging failed too; a report must never stop the node loading
         pass
 
 __all__ = ["NODE_CLASS_MAPPINGS", "NODE_DISPLAY_NAME_MAPPINGS", "WEB_DIRECTORY"]
 
-# Print startup message with loaded tools
-print()
-print(f"\033[94m[ComfyUI-PromptManager] Version:\033[0m {get_version()}")
-for node_key, display_name in NODE_DISPLAY_NAME_MAPPINGS.items():
-    # ASCII only: a Windows console using a legacy code page cannot print emoji,
-    # and a UnicodeEncodeError here would abort loading the whole node.
-    print(f"  \033[94mLoaded:\033[0m {display_name}")
-print(f"\033[94mTotal: {len(NODE_CLASS_MAPPINGS)} tools loaded\033[0m")
-print()
+# One startup line. ASCII only: a Windows console using a legacy code page
+# cannot print emoji, and a UnicodeEncodeError here would abort loading the node.
+print(
+    f"\033[94m[ComfyUI-PromptManager] Version:\033[0m {get_version()}"
+    f" - {len(NODE_CLASS_MAPPINGS)} tools loaded"
+)

database/library_move.py

@@ -78,6 +78,10 @@ MESSAGES = {
     ),
     "same-folder": "The new folder is the node folder itself.",
     "target-invalid": "The new folder cannot hold the library.",
+    "data-dir-served": (
+        "The new folder is inside Prompt Manager's thumbnail folder. Nothing was "
+        "moved."
+    ),
     "target-has-library": (
         "The new folder already holds a Prompt Manager library. Nothing was moved."
     ),
@@ -590,6 +594,7 @@ class _Move:
             try:
                 os.rmdir(self.plan.target_dir)
             except OSError:
+                # not empty or already gone: the undo leaves it alone
                 pass
 
 

database/managed_connection.py

@@ -35,38 +35,51 @@ from __future__ import annotations
 
 import contextlib
 import logging
+import operator
+import sys
 import threading
 import time
 import weakref
-from typing import Iterable, Iterator, List, Optional
+from collections import deque
+from typing import Any, Callable, Iterable, Iterator, List, Optional
 
 import sqlite3
 
 CLOSED_MESSAGE = "Cannot operate on a closed database."
 # Rows fetched per step when a cursor is iterated: the connection is marked
 # in use once per chunk instead of once per row (iteration costs about what
-# a plain cursor costs). A loop that stops early leaves up to this many rows
-# fetched; ``fetchone``/``fetchmany`` after a partial loop skip them.
+# a plain cursor costs). Prefetched rows belong to the cursor so iteration
+# and explicit fetches always advance the same position.
 ITER_CHUNK = 128
 
 
 class ManagedCursor(sqlite3.Cursor):
     """A cursor whose calls into SQLite count as its connection being in use."""
 
+    def __init__(self, *args: Any, **kwargs: Any) -> None:
+        super().__init__(*args, **kwargs)
+        self._pending = deque()
+        self._closed = False
+
     def execute(self, sql, parameters=(), /):
-        conn = self.connection
-        conn._enter()
-        try:
-            return super().execute(sql, parameters)
-        finally:
-            conn._leave()
+        return self._run_statement(super().execute, sql, parameters)
 
     def executemany(self, sql, seq_of_parameters, /):
+        return self._run_statement(super().executemany, sql, seq_of_parameters)
+
+    def _run_statement(self, operation: Callable, *args: Any) -> ManagedCursor:
         conn = self.connection
         conn._enter()
+        description = self.description
+        completed = False
         try:
-            return super().executemany(sql, seq_of_parameters)
+            result = operation(*args)
+            completed = True
+            return result
         finally:
+            # Argument parsing can fail before SQLite replaces the old statement.
+            if completed or self.description is not description:
+                self._pending.clear()
             conn._leave()
 
     def executescript(self, sql_script, /):
@@ -81,6 +94,8 @@ class ManagedCursor(sqlite3.Cursor):
         conn = self.connection
         conn._enter()
         try:
+            if self._pending and not self._closed:
+                return self._pending.popleft()
             return super().fetchone()
         finally:
             conn._leave()
@@ -89,7 +104,20 @@ class ManagedCursor(sqlite3.Cursor):
         conn = self.connection
         conn._enter()
         try:
-            return super().fetchmany(*args, **kwargs)
+            # Let SQLite validate the original arguments, including version-specific
+            # handling of zero/negative sizes, before touching prefetched rows.
+            rows = super().fetchmany(*args, **kwargs)
+            if not self._pending:
+                return rows
+            size = operator.index(
+                kwargs.get("size", args[0] if args else self.arraysize)
+            )
+            # Python 3.12 reads all rows for size=0; 3.13+ reads none.
+            if size == 0 and sys.version_info >= (3, 13):
+                return rows
+            self._pending.extend(rows)
+            count = len(self._pending) if size <= 0 else min(size, len(self._pending))
+            return [self._pending.popleft() for _ in range(count)]
         finally:
             conn._leave()
 
@@ -97,25 +125,31 @@ class ManagedCursor(sqlite3.Cursor):
         conn = self.connection
         conn._enter()
         try:
-            return super().fetchall()
+            rows = super().fetchall()
+            pending = list(self._pending)
+            self._pending.clear()
+            return pending + rows
         finally:
             conn._leave()
 
     def __iter__(self) -> Iterator:
-        return self._chunks()
-
-    def _chunks(self) -> Iterator:
-        while True:
-            rows = self.fetchmany(ITER_CHUNK)
-            if not rows:
-                return
-            yield from rows
+        return self
 
     def __next__(self):
         conn = self.connection
+        pending = self._pending
+        # Buffered Python rows need no SQLite lock, but retirement and cursor
+        # close must still stop an iterator obtained before either operation.
+        if conn._retired or self._closed:
+            raise sqlite3.ProgrammingError(CLOSED_MESSAGE)
+        if pending:
+            return pending.popleft()
         conn._enter()
         try:
-            return super().__next__()
+            pending.extend(super().fetchmany(ITER_CHUNK))
+            if not pending:
+                raise StopIteration
+            return pending.popleft()
         finally:
             conn._leave()
 
@@ -126,7 +160,10 @@ class ManagedCursor(sqlite3.Cursor):
         except sqlite3.ProgrammingError:
             return super().close()  # the connection is closed or closing
         try:
-            return super().close()
+            result = super().close()
+            self._pending = deque()
+            self._closed = True
+            return result
         finally:
             conn._leave()
 
@@ -293,6 +330,9 @@ class ManagedConnection(sqlite3.Connection):
             cursors = list(self._cursors)
         try:
             for cursor in cursors:
+                if isinstance(cursor, ManagedCursor):
+                    cursor._pending = deque()
+                    cursor._closed = True
                 with contextlib.suppress(sqlite3.Error):
                     sqlite3.Cursor.close(cursor)
             super().close()

database/operations.py

@@ -34,7 +34,7 @@ from .history_reads import HistoryReadOperations
 from .health import HealthOperations, iter_consistency_issues
 from .duplicate_copies import DuplicateCopyOperations
 from .workflow_storage import WorkflowStorageOperations
-from .category_import import CategoryImportOperations, EmptyReplacement  # noqa: F401
+from .category_import import CategoryImportOperations
 from .image_categories import ImageCategoryOperations
 from .workflow_documents import (
     DocumentReader,

database/safety_backup.py

@@ -46,6 +46,7 @@ def remove_quietly(*paths):
             if path and os.path.exists(path):
                 os.remove(path)
         except OSError:
+            # cleanup after a failure must not replace that failure
             pass
 
 

database/vocabulary.py

@@ -66,7 +66,6 @@ def _tag_rows(page: str, order: str = "page.id") -> str:
     )
 
 
-_TAG_PAGE = _tag_rows("SELECT id,name FROM tags WHERE id>? ORDER BY id LIMIT ?")
 # #444 tag sorts: sort -> (key expression on tags/counted, direction). Ties and
 # "created" follow the id, so every order is total and keyset pages are exact.
 TAG_SORTS = {

py/api/__init__.py

@@ -11,6 +11,7 @@ Split into domain-specific mixins for maintainability:
 - JobRoutesMixin: the session job registry behind Activity (py/api/jobs.py)
 - ImageTagJobsMixin: bulk Add tags / Auto-tag as image-tags jobs
 - ThumbnailJobsMixin: thumbnail plan, thumbnail job and the gallery stream on it
+- ThumbnailLocationMixin: the thumbnail location check and payloads (#320)
 - ThumbnailConvertMixin: Convert outdated thumbnails (#317), a thumbnail job mode
 - AutoThumbnailMixin: previews made on first view, on capture and after a scan
 - ReviewRoutesMixin: the Needs review queue, item detail and decisions
@@ -60,6 +61,7 @@ from .settings_routes import SettingsRoutesMixin
 from .job_routes import JobRoutesMixin
 from .image_tag_jobs import ImageTagJobsMixin
 from .thumbnail_jobs import ThumbnailJobsMixin
+from .thumbnail_location import ThumbnailLocationMixin
 from .thumbnail_convert import ThumbnailConvertMixin
 from .thumbnail_auto import AutoThumbnailMixin
 from .system import SystemRoutesMixin
@@ -85,6 +87,8 @@ try:
     from ...database.operations import PromptDatabase
     from ...utils.file_prompt import parse_comfyui_prompt
     from ...utils.logging_config import get_logger
+    from ...utils.native_memory import release_free_memory
+    from ...utils.png_text import png_text
     from ...utils.video_metadata import is_video_path, read_video_metadata
 except ImportError:
     import sys
@@ -95,6 +99,8 @@ except ImportError:
     from database.operations import PromptDatabase
     from utils.file_prompt import parse_comfyui_prompt
     from utils.logging_config import get_logger
+    from utils.native_memory import release_free_memory
+    from utils.png_text import png_text
     from utils.video_metadata import is_video_path, read_video_metadata
 
 
@@ -334,6 +340,7 @@ class PromptManagerAPI(
     JobRoutesMixin,
     ImageTagJobsMixin,
     ThumbnailJobsMixin,
+    ThumbnailLocationMixin,
     ThumbnailConvertMixin,
     AutoThumbnailMixin,
     SystemRoutesMixin,
@@ -526,6 +533,14 @@ class PromptManagerAPI(
             return await loop.run_in_executor(None, call)
         return await loop.run_in_executor(None, func, *args)
 
+    async def _release_job_memory(self):
+        """After a scan or thumbnail job: glibc's free heap pages go back to
+        the OS once (``malloc_trim(0)``; nothing elsewhere, #523)."""
+        try:
+            await self._run_in_executor(release_free_memory)
+        except Exception:  # best effort: the job's result already stands
+            self.logger.debug("Releasing free memory failed", exc_info=True)
+
     def _root_listing(self, root) -> RootListing:
         """The shared listing record of one output root (created empty)."""
         return self._root_listings.setdefault(str(root), RootListing())
@@ -840,20 +855,11 @@ class PromptManagerAPI(
                         f"{url_quote(rel_path.as_posix(), safe='/')}"
                     )
 
-                    # Any preview the file owns, the current format first (#317)
-                    from . import thumbnail_settings
-                    from .prompts import thumbnail_url_for
+                    # Any preview the file owns, the current format first
+                    # (#317); no store I/O here in folder mode (#320).
+                    from .images import listing_thumbnail_url
 
-                    existing = thumbnail_settings.existing_thumbnail(
-                        output_path, rel_path
-                    )
-                    thumbnail_url = None
-                    if existing is not None:
-                        thumb_rel = (
-                            thumbnail_settings.thumbnail_stem_rel(rel_path)
-                            + existing.suffix
-                        )
-                        thumbnail_url = thumbnail_url_for(thumb_rel, existing)
+                    thumbnail_url = listing_thumbnail_url(output_path, rel_path)
                     if thumbnail_url:
                         image["thumbnail_url"] = thumbnail_url
                     break  # Found matching root, stop searching
@@ -1048,6 +1054,8 @@ class PromptManagerAPI(
     def _extract_comfyui_metadata(self, image_path):
         """Embedded ComfyUI metadata of an image (PNG text chunks) or a video.
 
+        PNG text is read without decoding the pixels (``utils.png_text``, #523).
+
         Videos go through ffprobe (see utils/video_metadata). Unreadable files
         are a warning, not an error: a scan over a large output tree meets
         truncated and foreign files, and it carries on past them.
@@ -1056,7 +1064,7 @@ class PromptManagerAPI(
             return read_video_metadata(image_path)
         try:
             with Image.open(image_path) as img:
-                return dict(getattr(img, "text", None) or {})
+                return png_text(img)
         except Exception as e:
             self.logger.warning(
                 f"Unreadable image {os.path.basename(str(image_path))}: {e}"

py/api/admin.py

@@ -176,7 +176,7 @@ def _physical_file_key(path, stat):
     volumes on Windows) falls back to the resolved, case-folded path.
     """
     if stat.st_ino:
-        return ("inode", stat.st_dev, stat.st_ino)
+        return ("inode", (stat.st_dev, stat.st_ino))
     return ("path", os.path.normcase(os.path.realpath(str(path))))
 
 
@@ -539,6 +539,7 @@ def _diagnose_output_dirs(configured_dirs, public_path=None):
 
         candidates.append(folder_paths.get_output_directory())
     except ImportError:
+        # outside ComfyUI there is no output folder to add
         pass
 
     output_dirs = []
@@ -1453,6 +1454,7 @@ class AdminRoutesMixin:
             verb = "cancelled" if state == "cancelled" else "finished"
             job.log_line(f"Scan {verb} · {_plural(job.processed, 'file')} processed")
         job.finish(state)
+        await self._release_job_memory()
         if state == "finished":
             # After the scan, so the guarded thumbnail job is admitted (#249).
             await self._hand_off_scan_thumbnails(job, output_dirs)
@@ -1667,9 +1669,10 @@ class AdminRoutesMixin:
     def _extract_batch_metadata_sync(self, file_batch):
         """Extract metadata from a batch of files in one executor call.
 
-        Files are read on ``PromptManagerConfig.WORKER_THREADS`` threads:
-        Pillow decodes the whole image to reach trailing text chunks and
-        releases the GIL while doing so.
+        Files are read on the long-lived job pool of
+        ``PromptManagerConfig.WORKER_THREADS`` threads (#523).
+        PNG text is read chunk by chunk without decoding pixels (#523); file
+        reads and ffprobe release the GIL.
         """
         from ..config import PromptManagerConfig
 

py/api/annotation_suggest.py

@@ -13,7 +13,6 @@ import math
 from ..tagging_defaults import (  # noqa: F401 - re-exported for the route
     LLM_MODEL_TYPES as LLM_MODELS,
     MAX_INSTRUCTION_BYTES,
-    MAX_INSTRUCTION_CHARS,
     MODEL_TYPES,
     WD14_MODEL_TYPES as WD14_MODELS,
     validate_template,

py/api/autotag_routes.py

@@ -19,8 +19,8 @@ from .jobs import (
 )
 
 from .maintenance import disk_plan
-from .prompts import thumbnail_url_for
-from . import thumbnail_settings
+from .images import listing_thumbnail_url
+from . import preview_store
 from .. import model_gate
 
 try:
@@ -424,6 +424,7 @@ class AutotagRoutesMixin:
         title = f"Tagging model download · {label}"
         _download_titles.clear()
         _download_titles[owner] = title
+        admitted = False
         try:
             job = self._jobs.start(
                 MODEL_DOWNLOAD_JOB_KIND,
@@ -439,13 +440,13 @@ class AutotagRoutesMixin:
                     self._run_model_download, service, model_type, owner
                 ),
             )
-        except BaseException as refused:
-            # JobBusy, or anything else the registry raised: give the gate back.
-            model_gate.release(owner)
-            _download_titles.pop(owner, None)
-            if isinstance(refused, JobBusy):
-                return None, busy_response(refused)
-            raise
+            admitted = True
+        except JobBusy as refused:
+            return None, busy_response(refused)
+        finally:
+            if not admitted:  # JobBusy, or anything else: give the gate back.
+                model_gate.release(owner)
+                _download_titles.pop(owner, None)
 
         def ended(_task):
             model_gate.release(owner)
@@ -1041,12 +1042,12 @@ class AutotagRoutesMixin:
                 return self._bad_request('existing must be "skip" or "merge"')
             try:
                 options = self._single_options(data, model_type)
+            except OptionError as error:
+                return self._bad_request(str(error))
             except (ValueError, TypeError):
                 return self._bad_request(
                     "general_threshold and character_threshold must be numeric"
                 )
-            except OptionError as error:
-                return self._bad_request(str(error))
             target, error = await self._select_autotag_target(data)
             if error is not None:
                 return error
@@ -1370,23 +1371,21 @@ class AutotagRoutesMixin:
             files = await self._run_in_executor(
                 self._without_removed, output_path, files
             )
-            has_thumbnails = (output_path / "thumbnails").is_dir()
+            location = preview_store.current()
+            if location.mode == preview_store.FOLDER_MODE:
+                has_thumbnails = location.available  # no store I/O here (#320)
+            else:
+                store = preview_store.store_dir(output_path)
+                has_thumbnails = store is not None and store.is_dir()
 
             images = []
             for image_path in files:
                 rel_path = image_path.relative_to(output_path)
                 thumbnail_url = None
                 if has_thumbnails:
-                    # Any preview the file owns, the current format first (#317)
-                    existing = thumbnail_settings.existing_thumbnail(
-                        output_path, rel_path
-                    )
-                    if existing is not None:
-                        thumb_rel = (
-                            thumbnail_settings.thumbnail_stem_rel(rel_path)
-                            + existing.suffix
-                        )
-                        thumbnail_url = thumbnail_url_for(thumb_rel, existing)
+                    # Any preview the file owns, the current format first
+                    # (#317); in folder mode without store I/O (#320).
+                    thumbnail_url = listing_thumbnail_url(output_path, rel_path)
                 images.append(
                     {
                         "filename": image_path.name,

py/api/backup_restore.py

@@ -971,6 +971,7 @@ class BackupRestoreRoutesMixin:
         line = restored_line(staged.summary)
         job.log_line(line)
         job.update(progress=100, status_line=line)
+        return None
 
 
 async def _outlive_cancel(future):

py/api/duplicate_files.py

@@ -574,12 +574,13 @@ class DuplicateFilesMixin:
             return _fail_job(job, "sources-changed", SOURCES_CHANGED)
         ok, backup = await self._safety_backup_step(job, db, backup_on)
         if not ok:
-            return
+            return None
         try:
             await self._remove_duplicates(job, db, plan, backup)
         finally:
             if backup:
                 await self._prune_backup_pool(job, db)
+        return None
 
     async def _remove_duplicates(self, job, db, plan, backup):
         targets = plan.payload["targets"]

py/api/duplicate_spellings.py

@@ -27,7 +27,7 @@ def _identity(path):
     except OSError:
         return None
     if info.st_ino:
-        return ("inode", info.st_dev, info.st_ino)
+        return ("inode", (info.st_dev, info.st_ino))
     return ("path", os.path.normcase(os.path.realpath(str(path))))
 
 

py/api/history.py

@@ -843,7 +843,10 @@ class HistoryRoutesMixin:
                 raise
 
         async def execute():
-            pending = asyncio.create_task(self._run_in_executor(project))
+            # An inspection reads the file's header and text: the
+            # interactive image pool (#523); media stays on the default.
+            run = self._run_image if kind == "inspection" else self._run_in_executor
+            pending = asyncio.create_task(run(project))
             try:
                 return await asyncio.shield(pending)
             except asyncio.CancelledError:

py/api/history_current.py

@@ -15,10 +15,10 @@ from typing import BinaryIO
 
 from aiohttp import web
 
-from . import thumbnail_settings
+from . import preview_store, thumbnail_settings
 from .images import _canonical, _public_path, SERVABLE_EXTENSIONS, VIDEO_EXTENSIONS
 from .images import in_trash_below_roots
-from .images import existing_media_thumbnail, media_thumbnail_rel
+from .images import existing_media_thumbnail, media_preview_path
 
 try:
     from ...utils.execution_outputs import (
@@ -244,19 +244,36 @@ def resolve_current_candidate(
         return _unavailable("temporary_unavailable", error=True)
 
 
+def _target_authorized(target, namespace, scope, store_root=None) -> bool:
+    """A preview in the thumbnail folder (#320, folder mode) is authorized by
+    the store of its source (``preview_store.owns``: inside the key folder,
+    no link); everything else by the output namespace and the roots."""
+    if (
+        store_root is not None
+        and preview_store.current().mode == preview_store.FOLDER_MODE
+    ):
+        return preview_store.owns(store_root, target)
+    return _authorized(target, namespace, scope)
+
+
 def _open_current_target(
-    target: Path, namespace: Path, scope: CurrentOutputScope, preview: bool = False
+    target: Path,
+    namespace: Path,
+    scope: CurrentOutputScope,
+    preview: bool = False,
+    store_root: Path | None = None,
 ) -> BinaryIO:
     """Open only the canonical target and verify authority against the actual handle.
 
-    A *preview* (a file under ``thumbnails/``) may also be JPEG XL (#317)."""
+    A *preview* (a file under ``thumbnails/``) may also be JPEG XL (#317); in
+    folder mode it is authorized by the store of *store_root* (#320)."""
     if _canonical(target) != target:
         raise CurrentLocationUnavailable("not_authorized", stale=True)
     if in_trash_below_roots(target, [namespace]):
         # Also at the open: the cover chooses its preview after the candidate
         # check, and a preview can be a link into a trash folder (#543).
         raise CurrentLocationUnavailable("missing")
-    if not _authorized(target, namespace, scope):
+    if not _target_authorized(target, namespace, scope, store_root):
         raise CurrentLocationUnavailable("not_authorized")
     suffix = target.suffix.lower()
     if suffix not in SERVABLE_EXTENSIONS and not (
@@ -289,7 +306,7 @@ def _open_current_target(
         if (
             _canonical(target) != target
             or (observed.st_dev, observed.st_ino) != (current.st_dev, current.st_ino)
-            or not _authorized(target, namespace, scope)
+            or not _target_authorized(target, namespace, scope, store_root)
         ):
             raise CurrentLocationUnavailable("not_authorized", stale=True)
         return os.fdopen(fd, "rb")
@@ -326,12 +343,10 @@ class _OpenedCurrentMedia:
 
 
 def _preview_writable(root: Path, preview: Path) -> bool:
-    """A preview may be written: ``thumbnails`` and every link segment of the
-    preview's folder resolve inside *root* (the serve route's rule, #249)."""
-    folder = root / "thumbnails"
-    return _canonical(folder).is_relative_to(_canonical(root)) and _canonical(
-        preview
-    ).is_relative_to(_canonical(folder))
+    """A preview may be written: the store of *root* and every link segment
+    of the preview's folder resolve inside it (the serve route's rule, #249;
+    ``preview_store.owns``)."""
+    return preview_store.owns(root, preview)
 
 
 def _is_jxl(path) -> bool:
@@ -381,8 +396,12 @@ def _cover_target(resolved, ensure_preview, placeholder, accepts_jxl):
         return _canonical(preview)
     if preview is not None:
         return _canonical(preview)
-    preview = resolved.gallery_root / media_thumbnail_rel(relative)
-    if ensure_preview is not None and _preview_writable(resolved.gallery_root, preview):
+    preview = media_preview_path(resolved.gallery_root, relative, create=True)
+    if (
+        ensure_preview is not None
+        and preview is not None
+        and _preview_writable(resolved.gallery_root, preview)
+    ):
         ensure_preview(target, preview, is_video)
     if is_video and placeholder is not None:
         return _placeholder_media(placeholder)
@@ -418,7 +437,13 @@ def _prepare_current_media(
             return chosen
         if chosen is not None:
             target, is_preview = chosen, True
-    handle = _open_current_target(target, resolved.namespace, scope, is_preview)
+    handle = _open_current_target(
+        target,
+        resolved.namespace,
+        scope,
+        is_preview,
+        resolved.gallery_root if is_preview else None,
+    )
     try:
         return _OpenedCurrentMedia(
             handle,

py/api/image_delete.py

@@ -330,12 +330,13 @@ class ImageDeleteMixin:
             return _fail_job(job, "sources-changed", SOURCES_CHANGED)
         ok, backup = await self._safety_backup_step(job, db, backup_on)
         if not ok:
-            return
+            return None
         try:
             await self._delete_images(job, db, targets, mode, backup)
         finally:
             if backup:
                 await self._prune_backup_pool(job, db)
+        return None
 
     async def _delete_images(self, job, db, targets, mode, backup):
         job.update(total=len(targets), status_line=TITLES[mode])

py/api/image_tag_jobs.py

@@ -531,6 +531,7 @@ class ImageTagJobsMixin:
         run = AutotagRun(
             model_type, existing, options, keep_in_memory, backup_on, owner
         )
+        admitted = False
         try:
             job = self._jobs.start(
                 AUTOTAG_BATCH_JOB_KIND,
@@ -541,11 +542,12 @@ class ImageTagJobsMixin:
                 groups=AUTOTAG_GROUP_NAMES,
                 runner=functools.partial(self._run_autotag_batch, run),
             )
-        except BaseException as refused:
-            model_gate.release(owner)
-            if isinstance(refused, JobBusy):
-                return None, _busy_refusal(refused)
-            raise
+            admitted = True
+        except JobBusy as refused:
+            return None, _busy_refusal(refused)
+        finally:
+            if not admitted:
+                model_gate.release(owner)
         job.task.add_done_callback(lambda _task: model_gate.release(owner))
         return job, None
 

py/api/images.py

@@ -34,15 +34,14 @@ from .gallery_listing import (
     WalkOutcome,
     walk_root,
 )
-from . import thumbnail_settings
+from . import preview_store, thumbnail_settings
+from .thumbnail_location import location_refusal
 from .thumbnail_encode import (
     PREVIEW_HELD,
     EncoderClosed,
     PreviewWriteHeld,
-    replace_unless_held,
     run_encoder,
     sweep_stray_temps,
-    temp_sibling,
     thumbnail_frame,
     writer_settings,
     write_thumbnail,
@@ -339,11 +338,6 @@ def _thumbnail_batch_size(workers):
     return max(4, workers * 2)
 
 
-# Preview files are written by thumbnail_encode in the configured format
-# (thumbnail_settings, #317); these names stay importable from here.
-_temp_sibling = temp_sibling
-_replace_unless_held = replace_unless_held
-
 # A preview that could not be replaced (#249 S5 M6). Windows refuses to rename
 # over a file another process has open (WinError 5 or 32), such as a preview
 # the gallery is serving; the old preview stays and the file counts as an error.
@@ -396,6 +390,7 @@ def _video_placeholder_image(thumbnail_size):
             font=font,
         )
     except (OSError, AttributeError):
+        # a placeholder without its label still works
         pass
     return img
 
@@ -499,6 +494,7 @@ def _preview_names(folders, folder):
                     except OSError:
                         continue
         except OSError:
+            # an unreadable folder lists as empty; nothing there to cache
             pass
         folders[folder] = names
     return names
@@ -1073,13 +1069,24 @@ def _iter_media_files(output_path, max_files):
 
 
 def media_thumbnail_rel(rel_path, settings=None):
-    """``thumbnails/<rel>_thumb<ext>`` (POSIX) for the media file *rel_path*:
-    the name the preview gets when it is written now (#317), images and
-    videos alike (``writer_settings``' extension)."""
+    """``thumbnails/<rel>_thumb<ext>`` (POSIX URL text) for the media file
+    *rel_path*: the name the preview gets when it is written now (#317),
+    images and videos alike (``writer_settings``' extension). Where it is on
+    disk is ``media_preview_path``."""
     settings = settings or writer_settings()
     return thumbnail_settings.thumbnail_rel(rel_path, settings.extension)
 
 
+def media_preview_path(output_path, rel_path, settings=None, *, create=False):
+    """Where the preview of *rel_path* is written now (``preview_store``);
+    *create* for a writer (a new source gets its key). None when nothing
+    may be written (the thumbnail folder is unavailable)."""
+    settings = settings or writer_settings()
+    return preview_store.preview_path(
+        output_path, rel_path, settings.extension, create=create
+    )
+
+
 def existing_media_thumbnail(output_path, rel_path):
     """The existing preview *rel_path* owns that a listing or cover shows
     (the format written now first, then older ones), or None. The Images
@@ -1089,6 +1096,27 @@ def existing_media_thumbnail(output_path, rel_path):
     )
 
 
+def listing_thumbnail_url(output_path, rel_path):
+    """The thumbnail URL of an older listing (``_enrich_images``, the
+    auto-tag scan), or None. These run on the event loop: in folder mode
+    (#320) the store is never touched there, so the URL names the preview
+    as it is written now and the serve route finds or makes it off the loop
+    (None while the thumbnail folder is unavailable)."""
+    from .prompts import thumbnail_url_for
+
+    location = preview_store.current()
+    if location.mode == preview_store.FOLDER_MODE:
+        if not location.available:
+            return None
+        quoted = urllib.parse.quote(media_thumbnail_rel(rel_path), safe="/")
+        return f"/prompt_manager/images/serve/{quoted}"
+    existing = thumbnail_settings.existing_thumbnail(output_path, rel_path)
+    if existing is None:
+        return None
+    thumb_rel = thumbnail_settings.thumbnail_stem_rel(rel_path) + existing.suffix
+    return thumbnail_url_for(thumb_rel, existing)
+
+
 def media_thumbnail(output_path, rel_path, root_index, *, root_scope=None):
     """``(thumbnail_url, ready)`` for *rel_path* under *output_path* (a few
     blocking stats). The Images listing, the Needs review queue cards and the
@@ -2803,13 +2831,56 @@ class ImageRoutesMixin:
                     output_dirs[0], filepath, int(root_param), len(outputs)
                 )
 
+            # Preview text is mapped by the resolver (#320); any other text,
+            # ``Thumbnails/...`` media on a case-sensitive disk included,
+            # keeps the plain join.
+            preview_parts = (
+                tuple(filepath.split("/"))
+                if preview_store.is_preview_text(filepath)
+                else None
+            )
+            location = preview_store.current()
+            if location.mode == preview_store.FOLDER_MODE:
+                if preview_parts is None and await self._run_image(
+                    self._in_source_thumbnails, output_dirs, filepath
+                ):
+                    # Previews live in the thumbnail folder: anything else
+                    # under a source's thumbnails/ is a leftover (#320), in
+                    # any case on a case-insensitive disk.
+                    return _forbidden()
+                if preview_parts is not None:
+                    # Store I/O never runs on the event loop (a share may
+                    # stall): the lookup runs on the image pool.
+                    found = await self._run_image(
+                        self._find_preview, output_dirs, preview_parts, location
+                    )
+                    if found == "forbidden":
+                        return _forbidden()
+                    if found is not None:
+                        return self._file_response(found)
             for output_path in output_dirs:
-                image_path = output_path / filepath
+                if (
+                    preview_parts is not None
+                    and location.mode == preview_store.FOLDER_MODE
+                ):
+                    break  # looked up above
+                if preview_parts is None:
+                    image_path = output_path / filepath
+                else:
+                    image_path = preview_store.request_path(output_path, preview_parts)
+                    if image_path is None:
+                        continue
                 if not image_path.exists():
                     continue
-                # A symlink that points outside the root is a hard deny, not
-                # a fall-through to the next root.
-                if not _is_within(image_path, output_path):
+                # A symlink that points outside the root (a preview: outside
+                # the folder holding its store) is a hard deny, not a
+                # fall-through to the next root.
+                container = (
+                    output_path
+                    if preview_parts is None
+                    else preview_store.store_container(output_path)
+                )
+                if not _is_within(image_path, container):
                     return _forbidden()
                 if in_trash_below_roots(image_path, output_dirs):
                     return _file_not_found()
@@ -2835,6 +2906,48 @@ class ImageRoutesMixin:
                 {"success": False, "error": _safe_error(e)}, status=500
             )
 
+    @staticmethod
+    def _in_source_thumbnails(output_dirs, filepath):
+        """Whether *filepath* lies in a source's ``thumbnails`` folder: its
+        first part is ``thumbnails`` exactly, or another case of it that is
+        the same folder (a case-insensitive disk). ``Thumbnails/`` media on
+        a case-sensitive disk is another folder and stays served."""
+        first = filepath.split("/", 1)[0]
+        if first == "thumbnails":
+            return True
+        if first.casefold() != "thumbnails":
+            return False
+        for output_path in output_dirs:
+            spelled = output_path / first
+            cache = preview_store.source_folder(output_path)
+            try:
+                if spelled.is_dir() and cache.is_dir() and spelled.samefile(cache):
+                    return True
+            except OSError:
+                continue
+        return False
+
+    @staticmethod
+    def _find_preview(output_dirs, parts, location):
+        """The preview file *parts* names in folder mode, ``"forbidden"``
+        (it resolves out of its store or through a link) or None (blocking;
+        the first root whose store holds it, in ``_select_root`` order)."""
+        for output_path in output_dirs:
+            image_path = preview_store.request_path(output_path, parts, location)
+            if image_path is None:
+                continue
+            try:
+                with preview_store.store_io():
+                    if not os.path.lexists(image_path):
+                        continue
+                    if not preview_store.owns(output_path, image_path, location):
+                        return "forbidden"
+                    if image_path.is_file():
+                        return image_path
+            except OSError:
+                return None
+        return None
+
     def _is_recorded_media(self, path) -> bool:
         """Whether the database records ``path`` as a linked image.
 
@@ -2961,6 +3074,9 @@ class ImageRoutesMixin:
         data, error = await _json_body_or_error(request)
         if error is not None:
             return error
+        refused = location_refusal()
+        if refused is not None:
+            return refused
         return await self._run_held(
             THUMBNAILS_JOB_KIND,
             THUMBNAIL_GENERATION_TITLE,
@@ -2980,6 +3096,7 @@ class ImageRoutesMixin:
             result = await self._run_in_executor(
                 self._generate_gallery_thumbnails_sync, output_dirs
             )
+            await self._release_job_memory()
             return web.json_response(result)
 
         except Exception as e:
@@ -2992,6 +3109,7 @@ class ImageRoutesMixin:
         """Blocking thumbnail generation loop (run in executor)."""
         settings = writer_settings(settings)
         start = _time.monotonic()
+        thumbnails_dir = preview_store.given_store(output_path, thumbnails_dir)
         plan = self._plan_thumbnails(output_path, thumbnails_dir, settings=settings)
         payload = self._execute_thumbnail_plan(plan, settings, start)
         payload["thumbnails_path"] = _public_path(thumbnails_dir)
@@ -3004,7 +3122,8 @@ class ImageRoutesMixin:
         start = _time.monotonic()
         plan = self._plan_gallery_thumbnails(output_dirs, settings=settings)
         payload = self._execute_thumbnail_plan(plan, settings, start)
-        payload["thumbnails_path"] = _public_path(output_dirs[0] / "thumbnails")
+        store = preview_store.store_dir(output_dirs[0])
+        payload["thumbnails_path"] = None if store is None else _public_path(store)
         return payload
 
     def _execute_thumbnail_plan(self, plan: dict, settings, start: float) -> dict:
@@ -3047,9 +3166,12 @@ class ImageRoutesMixin:
             if stop is not None and stop():
                 break
             root = Path(root)
+            store = preview_store.ensure_store(root)
+            if store is None:
+                continue  # the thumbnail folder is unavailable
             plan = self._plan_thumbnails(
                 root,
-                root / "thumbnails",
+                store,
                 mode=mode,
                 stop=stop,
                 settings=settings,
@@ -3088,6 +3210,8 @@ class ImageRoutesMixin:
                     "format": writer_settings().format,
                     # Files whose automatic preview failed this session (#249).
                     "failed": self._auto_thumbnail_failures(),
+                    # #320: where previews live (no path here, D6A).
+                    "location": self._thumbnail_location_payload(with_path=False),
                     "collection_id": hashlib.sha256(collection.encode()).hexdigest()[
                         :16
                     ],
@@ -3133,9 +3257,11 @@ class ImageRoutesMixin:
         """
         settings = writer_settings(settings)
         output_path = Path(output_path)
-        thumbnails_dir = Path(thumbnails_dir)
+        thumbnails_dir = preview_store.given_store(output_path, thumbnails_dir)
         plan = {key: 0 for key in _PLAN_COUNTS}
         plan.update(targets=[], fresh_files=[])
+        if thumbnails_dir is None:
+            return plan  # the thumbnail folder is unavailable
         folders = {}
         removed = self._removal_check_under(output_path)
         for src in _iter_media_files(output_path, MAX_GALLERY_FILES):
@@ -3225,6 +3351,9 @@ class ImageRoutesMixin:
             "dir": src.parent.name,
             "type": "video" if is_video else "image",
         }
+        # Taken when the write starts: a thumbnail location switched since
+        # then drops the write at its rename (#320).
+        guard = preview_store.write_guard(guard)
         dst = Path(dst)
         if dst.suffix != settings.extension:
             dst = dst.with_suffix(settings.extension)
@@ -3235,7 +3364,7 @@ class ImageRoutesMixin:
                 return {**result, "action": "error", "error": "File no longer exists"}
             if not rebuild and _thumbnail_is_fresh(src, dst):
                 return {**result, "action": "skipped", "path": str(dst)}
-            dst.parent.mkdir(parents=True, exist_ok=True)
+            preview_store.make_parent(dst)
             if is_video:
                 made = self._generate_video_thumbnail(
                     src,
@@ -3440,8 +3569,12 @@ class ImageRoutesMixin:
 
         Invalid thumbnail directories return 400; unavailable gallery roots
         return 404, and unexpected filesystem failures return 500. Holds the
-        registry as guarded work, like generation.
+        registry as guarded work, like generation. Refused (409) while the
+        thumbnail folder is unavailable (#320).
         """
+        refused = location_refusal()
+        if refused is not None:
+            return refused
         return await self._run_held(
             THUMBNAILS_JOB_KIND,
             THUMBNAIL_CLEAR_TITLE,
@@ -3505,8 +3638,12 @@ class ImageRoutesMixin:
             self.logger.debug(f"No roots to sweep for preview temp files: {exc}")
             return 0
         for output_path in output_dirs:
-            folder = Path(output_path) / "thumbnails"
-            if folder.is_symlink() or not folder.is_dir():
+            folder = preview_store.store_dir(output_path)
+            if (
+                folder is None
+                or preview_store.store_is_link(folder)
+                or not folder.is_dir()
+            ):
                 continue
             removed += sweep_stray_temps(folder)[0]
         if removed:
@@ -3524,13 +3661,16 @@ class ImageRoutesMixin:
         directories = []
         for output_path in output_dirs:
             output_path = Path(output_path)
-            thumbnails_dir = output_path / "thumbnails"
+            thumbnails_dir = preview_store.store_dir(output_path)
+            if thumbnails_dir is None:
+                continue
             if not thumbnails_dir.exists() and not thumbnails_dir.is_symlink():
                 continue
+            container = preview_store.store_container(output_path)
             if (
-                thumbnails_dir.is_symlink()
-                or not _is_within(thumbnails_dir, output_path)
-                or _canonical(thumbnails_dir) == _canonical(output_path)
+                preview_store.store_is_link(thumbnails_dir)
+                or not _is_within(thumbnails_dir, container)
+                or _canonical(thumbnails_dir) == _canonical(container)
             ):
                 raise ValueError(
                     "Safety check failed: invalid thumbnails directory path"
@@ -3545,7 +3685,15 @@ class ImageRoutesMixin:
             temps, temp_bytes = sweep_stray_temps(thumbnails_dir, min_age=0)
             cleared_count += temps
             cleared_size += temp_bytes
-            for root, _dirs, files in os.walk(thumbnails_dir):
+            folder_mode = preview_store.current().mode == preview_store.FOLDER_MODE
+            for root, dirs, files in os.walk(thumbnails_dir):
+                if folder_mode:
+                    # Never into a junction or reparse point (#320).
+                    dirs[:] = [
+                        d
+                        for d in dirs
+                        if not preview_store.store_is_link(Path(root) / d)
+                    ]
                 for name in files:
                     path = Path(root) / name
                     if (
@@ -3553,6 +3701,7 @@ class ImageRoutesMixin:
                         or path.suffix.lower()
                         not in thumbnail_settings.THUMBNAIL_EXTENSIONS
                         or path.is_symlink()
+                        or not preview_store.may_write(path)
                     ):
                         continue
                     try:
@@ -4002,7 +4151,8 @@ class ImageRoutesMixin:
                     **observed,
                 )
 
-            body = await self._run_in_executor(inspect)
+            # Header and text reads: the interactive image pool (#523).
+            body = await self._run_image(inspect)
             if body is None:
                 return web.json_response(
                     {
@@ -4215,6 +4365,22 @@ class ImageRoutesMixin:
         # (which Windows refuses on open files) is not held up by it.
         return _CardFacts(width, height, *self._card_parse(path, records))
 
+    def _cached_card_facts(self, entry: tuple) -> _CardFacts | None:
+        path, mtime, root, index = entry[:4]
+        return self._workspace_card_cache.get((index, str(root)), {}).get((path, mtime))
+
+    def _card_facts_of(self, entries: list, *, parse: bool) -> list[_CardFacts]:
+        """Card facts of *entries*, in order; files not cached yet are read on
+        the interactive image pool (#523), cached ones answer here."""
+        found = [self._cached_card_facts(entry) for entry in entries]
+        missing = [i for i, facts in enumerate(found) if facts is None]
+        read = self._map_image(
+            lambda i: self._card_facts(entries[i], parse=parse), missing
+        )
+        for i, facts in zip(missing, read):
+            found[i] = facts
+        return found
+
     def _card_facts(self, entry: tuple, *, parse: bool) -> _CardFacts:
         """One listed image's card facts, read once per ``(path, mtime)``.
 
@@ -4223,11 +4389,11 @@ class ImageRoutesMixin:
         and drops the rest, and a roots change drops them all. Only files of
         the current scan are stored, so the cache is bounded by the listing.
         """
-        path, mtime, root, index = entry[:4]
-        root_key, key = (index, str(root)), (path, mtime)
-        cached = self._workspace_card_cache.get(root_key, {}).get(key)
+        cached = self._cached_card_facts(entry)
         if cached is not None:
             return cached
+        path, mtime, root, index = entry[:4]
+        root_key, key = (index, str(root)), (path, mtime)
         facts = self._read_card_facts(path, parse=parse)
         if facts is None:
             # Not stored: a locked or half-written file may read next time.
@@ -4253,15 +4419,17 @@ class ImageRoutesMixin:
             if linked
             else {}
         )
+        # Videos: the card reads no video metadata. Library previews show
+        # no card facts, so they skip the parse (``parse=linked``).
+        stills = [image for image in images if not image["is_video"]]
+        read = self._card_facts_of(
+            [entries[(image["root_index"], image["path"])] for image in stills],
+            parse=linked,
+        )
+        facts_of = {id(image): facts for image, facts in zip(stills, read)}
         for image in images:
             entry = entries[(image["root_index"], image["path"])]
-            # Videos: the card reads no video metadata. Library previews show
-            # no card facts, so they skip the parse (``parse=linked``).
-            facts = (
-                _NO_CARD_FACTS
-                if image["is_video"]
-                else self._card_facts(entry, parse=linked)
-            )
+            facts = facts_of.get(id(image), _NO_CARD_FACTS)
             image["width"], image["height"] = facts.width, facts.height
             if not linked:
                 continue

py/api/job_routes.py

@@ -250,7 +250,7 @@ class JobRoutesMixin:
         try:
             await response.write(_summary_event(job))
             async with contextlib.aclosing(job.events()) as events:
-                async for _payload in events:
+                async for _ in events:
                     await response.write(_summary_event(job))
             # The last event is published before the job takes its final state.
             await response.write(_summary_event(job))

py/api/library_location.py

@@ -50,6 +50,7 @@ _REFUSAL_STATUS = {
     "not-movable": 400,
     "same-folder": 400,
     "target-invalid": 400,
+    "data-dir-served": 400,
     "target-has-library": 409,
     "target-conflict": 409,
     "insufficient-space": 507,
@@ -74,6 +75,16 @@ def _failure(message, status, code):
     )
 
 
+def _inside_thumbnail_folder(path):
+    """Whether *path* lies in the thumbnail folder in use (#320)."""
+    from . import preview_store
+
+    setting = preview_store.setting()
+    if setting.mode != preview_store.FOLDER_MODE or not setting.path:
+        return False
+    return ll._inside_any(path, [setting.path])
+
+
 def _plural(count, one, many=None):
     return f"{count:,} {one if count == 1 else (many or one + 's')}"
 
@@ -207,6 +218,7 @@ class LibraryLocationRoutesMixin:
         try:
             size = os.path.getsize(location.db_path)
         except OSError:
+            # no library file yet: report size 0
             pass
         return {
             "path": self._library_public_path(location.db_path),
@@ -271,6 +283,8 @@ class LibraryLocationRoutesMixin:
     def _plan_library_move(self):
         """The checked plan (blocking); raises MoveFailed."""
         plan = lm.plan_move(self._live_location())
+        if _inside_thumbnail_folder(plan.target_dir):
+            raise lm.MoveFailed("data-dir-served")
         if lm.space_problem(plan) is not None:
             raise lm.MoveFailed("insufficient-space")
         return plan
@@ -373,6 +387,7 @@ class LibraryLocationRoutesMixin:
         line += ". Logs move at the next restart."
         job.log_line(line)
         job.update(progress=100, status_line=line)
+        return None
 
     @staticmethod
     def _fail_library_move(job, code, message):

py/api/log_cleanup.py

@@ -205,3 +205,4 @@ class LogCleanupMixin:
             line += f", {failed} could not be deleted"
         job.log_line(line)
         job.update(processed=len(files), progress=100, status_line=line)
+        return None

py/api/lora_import_routes.py

@@ -436,7 +436,7 @@ class LoraImportRoutesMixin:
             job.log_line(f"{CANCELLED} {CACHE_NOTE}")
             job.update(status_line=CANCELLED)
             job.finish("cancelled")
-            return
+            return None
         except Exception:
             self.logger.exception("LoRA import staging failed")
             return _fail_job(job, "import-failed", f"{FAILED} {CACHE_NOTE}")
@@ -455,10 +455,10 @@ class LoraImportRoutesMixin:
             job.log_line(f"{CANCELLED} {CACHE_NOTE}")
             job.update(status_line=CANCELLED)
             job.finish("cancelled")
-            return
+            return None
         ok, _backup = await self._safety_backup_step(job, db, backup_on)
         if not ok:
-            return
+            return None
         # I1: the files are listed and fingerprinted again right before the
         # replace, so a file changed, removed or added while the downloads ran
         # (LoraManager refreshing its CivitAI info) aborts with nothing deleted.
@@ -466,6 +466,7 @@ class LoraImportRoutesMixin:
             return _fail_job(job, "plan-changed", f"{SOURCE_CHANGED} {CACHE_NOTE}")
         job.update(status_line="Replacing the LoRA collection", progress=95)
         await self._replace_in_job(job, db, plan, staged)
+        return None
 
     def _count_downloads(self, job, staged):
         downloaded = staged.stats.get("downloaded", 0)
@@ -518,3 +519,4 @@ class LoraImportRoutesMixin:
             staged.stats.get("download_errors", 0),
         )
         job.update(progress=100, processed=job.total, status_line=line)
+        return None

py/api/lora_integration.py

@@ -44,6 +44,7 @@ _FILES_CHANGED = (
     "The LoRA metadata files changed during the scan; the previous imports "
     "were kept. Run the scan again."
 )
+_LORA_SCAN_FAILED = "The LoRA import failed. Check the server log for details."
 _IMPORTS_CHANGED = (
     "The imported LoRA prompts changed during the scan; the previous imports "
     "were kept. Run the scan again."
@@ -407,10 +408,21 @@ class LoraIntegrationMixin:
             return
         if isinstance(error, PlanChanged):
             message = _IMPORTS_CHANGED
-        elif isinstance(error, (LoraFilesChanged, LoraSettingsUnusable)):
+        elif isinstance(
+            error,
+            (
+                LoraFilesChanged,
+                LoraSettingsUnusable,
+                EmptyReplacement,
+                PairDependencyError,
+            ),
+        ):
             message = str(error)
-        else:
+        elif isinstance(error, OSError):
+            # Reduced to its reason and the file's basename.
             message = self._public_error(error)
+        else:
+            message = _LORA_SCAN_FAILED
         if isinstance(
             error,
             (
@@ -536,6 +548,7 @@ class LoraIntegrationMixin:
                 except asyncio.CancelledError:
                     interrupted = True
                 except Exception:
+                    # the await after this loop raises it for the caller
                     pass
             if interrupted:
                 raise asyncio.CancelledError

py/api/maintenance.py

@@ -673,6 +673,7 @@ class MaintenanceRoutesMixin:
         line = _changed_line(plan.operation, result["changed"], result.get("marks", 0))
         job.log_line(line)
         job.update(progress=100, status_line=f"{line} · {backup_note(backup)}")
+        return None
 
     def _maintenance_rows(self, operation, described):
         """Outcome rows for the changed records (root-relative paths only)."""

py/api/preview_location.py

@@ -0,0 +1,643 @@
+"""The thumbnail location setting (#320): parsing, validation, source keys
+and the thumbnail folder's marker.
+
+``preview_store`` holds the runtime state and maps paths; this module holds
+the rules it applies. Nothing here keeps state.
+
+Schema (config.json ``thumbnails.location``)::
+
+    {"mode": "folder", "path": "D:\\\\Thumbs", "id": "<uuid4>",
+     "install": "<uuid4>", "cleanup": []}
+
+The default (and a missing key) is ``{"mode": "source"}``: previews inside
+each source. An invalid value never falls back to the sources: it parses as
+a folder location with problem ``invalid``, so nothing is written anywhere.
+
+Layout in folder mode: ``<folder>/<source key>/<rel dir>/<stem>_thumb<ext>``.
+A source key is a readable slug plus a short hash of the source's identity
+(``output-3f9a2c1b``), assigned once and stored in the marker
+``.promptmanager-thumbnails.json`` with the identity it belongs to.
+"""
+
+import errno
+import hashlib
+import json
+import logging
+import ntpath
+import os
+import posixpath
+import re
+import stat as stat_module
+import threading
+import unicodedata
+import uuid
+from dataclasses import dataclass, field
+
+try:
+    from ...utils import library_location
+except ImportError:  # tests import the package top-level
+    from utils import library_location
+
+logger = logging.getLogger("prompt_manager.thumbnails")
+
+SOURCE_MODE = "source"
+FOLDER_MODE = "folder"
+MARKER_NAME = ".promptmanager-thumbnails.json"
+MARKER_VERSION = 1
+# A source key: one folder name, a slug and a 8-16 hex hash (``source_key``).
+KEY_PATTERN = re.compile(r"^[a-z0-9_-]{1,24}-[0-9a-f]{8,16}$")
+# A marker is a few keys; anything larger is not ours.
+MAX_MARKER_BYTES = 4 * 2**20
+# OS metadata files a folder may hold and still count as empty.
+OS_METADATA = frozenset({"thumbs.db", "desktop.ini", ".ds_store"})
+KEY_HASH_LENGTHS = (8, 12, 16)
+SLUG_LENGTH = 24
+# Folder + the longest key (24 + 1 + 16) + this margin must fit (Windows).
+WINDOWS_FOLDER_LIMIT = 247
+LONGEST_KEY = SLUG_LENGTH + 1 + KEY_HASH_LENGTHS[-1]
+PATH_MARGIN = 40
+# A validation stat on a share that does not answer in time is unavailable.
+VALIDATION_TIMEOUT = 5.0
+FILE_ATTRIBUTE_REPARSE_POINT = 0x400
+
+_RESERVED = re.compile(r"^(con|prn|aux|nul|com[1-9]|lpt[1-9])(\..*)?$", re.IGNORECASE)
+_BAD_CHARS = re.compile(r'[<>:"|?*\x00-\x1f]')
+
+# Problem codes, their HTTP status and the text the UI shows (no path).
+MESSAGES = {
+    "location-not-absolute": (
+        400,
+        "Enter a full folder path, such as D:\\Thumbnails or /mnt/fast/thumbnails.",
+    ),
+    "location-device-path": (
+        400,
+        "Enter the folder as a drive letter or \\\\server\\share path, "
+        "without \\\\?\\.",
+    ),
+    "location-invalid-name": (
+        400,
+        "This folder name can't be used on Windows. Choose another name.",
+    ),
+    "location-too-broad": (
+        400,
+        "Choose a folder inside a drive or share, not the drive itself.",
+    ),
+    "location-served": (
+        400,
+        "Choose a folder outside your image sources and ComfyUI's output, input "
+        "and temp folders.",
+    ),
+    "location-node-folder": (
+        400,
+        "Choose a folder outside the Prompt Manager node folder.",
+    ),
+    "location-contains-source": (
+        400,
+        "This folder contains an image source. Choose a folder beside it instead.",
+    ),
+    "location-same": (400, "Thumbnails are already stored here."),
+    "location-parent-missing": (
+        400,
+        "The folder that would hold it doesn't exist. Check the path and that its "
+        "drive is connected.",
+    ),
+    "location-unavailable": (
+        409,
+        "This folder can't be reached right now. Check that its drive or share is "
+        "connected.",
+    ),
+    "location-not-empty": (
+        409,
+        "This folder already holds other files. Choose an empty folder or one "
+        "Prompt Manager used before.",
+    ),
+    "location-not-writable": (
+        409,
+        "Prompt Manager can't write to this folder. Check its permissions.",
+    ),
+    "location-path-too-long": (
+        400,
+        "This path is too long for Windows. Choose a shorter folder path.",
+    ),
+    "location-needs-move": (
+        409,
+        "Use Move thumbnails in System › Sources & scans.",
+    ),
+}
+HOLDS_THUMBNAILS_REASON = "This folder holds Prompt Manager's thumbnails."
+
+
+def message(code):
+    """``(status, text)`` of a problem code."""
+    return MESSAGES[code]
+
+
+# ── parsing ──────────────────────────────────────────────────────────
+
+
+@dataclass(frozen=True)
+class ParsedLocation:
+    """A ``thumbnails.location`` value, checked as data (no filesystem)."""
+
+    mode: str = SOURCE_MODE
+    path: str | None = None
+    id: str | None = None
+    install: str | None = None
+    cleanup: tuple = field(default_factory=tuple)
+    problem: str | None = None
+
+    def to_config(self):
+        """The config.json form (``invalid`` values are never written)."""
+        if self.mode == SOURCE_MODE:
+            value = {"mode": SOURCE_MODE}
+        else:
+            value = {"mode": FOLDER_MODE, "path": self.path, "id": self.id}
+        if self.install:
+            value["install"] = self.install
+        value["cleanup"] = list(self.cleanup)
+        return value
+
+
+def _cleanup(value):
+    if not isinstance(value, list):
+        return ()
+    return tuple(item for item in value if isinstance(item, dict))
+
+
+def parse_location(value, *, flavor=os.path):
+    """The location a ``thumbnails.location`` value names.
+
+    Missing: inside each source. Anything else that is not a well-formed
+    location (an unknown mode, a relative path, a missing id) becomes a
+    folder location with problem ``invalid``: never a silent fall-back.
+    """
+    if value is None:
+        return ParsedLocation()
+    if not isinstance(value, dict):
+        return ParsedLocation(mode=FOLDER_MODE, problem="invalid")
+    mode = value.get("mode", SOURCE_MODE)
+    install = value.get("install") if isinstance(value.get("install"), str) else None
+    cleanup = _cleanup(value.get("cleanup"))
+    if mode == SOURCE_MODE:
+        return ParsedLocation(install=install, cleanup=cleanup)
+    if mode != FOLDER_MODE:
+        return ParsedLocation(mode=FOLDER_MODE, problem="invalid", cleanup=cleanup)
+    path, marker_id = value.get("path"), value.get("id")
+    if (
+        not isinstance(path, str)
+        or form_problem(path, flavor=flavor) is not None
+        or not isinstance(marker_id, str)
+        or not marker_id.strip()
+    ):
+        return ParsedLocation(
+            mode=FOLDER_MODE,
+            path=path if isinstance(path, str) else None,
+            problem="invalid",
+            cleanup=cleanup,
+        )
+    return ParsedLocation(
+        mode=FOLDER_MODE,
+        path=flavor.abspath(path),
+        id=marker_id,
+        install=install,
+        cleanup=cleanup,
+    )
+
+
+# ── form (text only) ─────────────────────────────────────────────────
+
+
+def _is_windows(flavor):
+    return flavor is ntpath or getattr(flavor, "__name__", "") == "ntpath"
+
+
+def form_problem(path, *, flavor=os.path):
+    """The text-only problem of *path*, or None (no filesystem access).
+
+    ``\\\\?\\`` and ``\\\\.\\`` prefixes, relative, drive-relative (``C:x``)
+    and root-relative (``\\x``) spellings, and names Windows cannot hold
+    (checked on every OS: the folder may be moved to Windows).
+    """
+    if not isinstance(path, str) or not path.strip() or path != path.lstrip():
+        return "location-not-absolute"
+    if path.replace("/", "\\").startswith(("\\\\?\\", "\\\\.\\")):
+        return "location-device-path"
+    if _is_windows(flavor):
+        drive, rest = ntpath.splitdrive(path)
+        if not drive or not rest.startswith(("\\", "/")):
+            return "location-not-absolute"
+    elif not posixpath.isabs(path):
+        return "location-not-absolute"
+    drive, rest = flavor.splitdrive(path)
+    for part in re.split(r"[\\/]+", rest):
+        if not part:
+            continue
+        if (
+            _RESERVED.match(part)
+            or part.endswith((".", " "))
+            or _BAD_CHARS.search(part)
+        ):
+            return "location-invalid-name"
+    return None
+
+
+def is_too_broad(path, *, home=None, flavor=os.path):
+    """A filesystem or share root, or the home folder itself."""
+    normalized = flavor.normpath(path)
+    drive, rest = flavor.splitdrive(normalized)
+    if rest in ("", "\\", "/"):
+        return True
+    home = home if home is not None else os.path.expanduser("~")
+    return bool(home) and flavor.normcase(normalized) == flavor.normcase(
+        flavor.normpath(home)
+    )
+
+
+def too_long_for_windows(path, long_paths=None):
+    """Folder + the longest key + a margin over the folder limit (Windows
+    without long paths; *long_paths* injects the registry answer)."""
+    if long_paths is None:
+        long_paths = long_paths_enabled()
+    if long_paths:
+        return False
+    return len(path) + 1 + LONGEST_KEY + PATH_MARGIN > WINDOWS_FOLDER_LIMIT
+
+
+def long_paths_enabled():
+    """``LongPathsEnabled`` on Windows (True on other systems)."""
+    if os.name != "nt":
+        return True
+    try:
+        import winreg
+
+        with winreg.OpenKey(
+            winreg.HKEY_LOCAL_MACHINE,
+            r"SYSTEM\CurrentControlSet\Control\FileSystem",
+        ) as key:
+            return winreg.QueryValueEx(key, "LongPathsEnabled")[0] == 1
+    except OSError:
+        return False
+
+
+# ── links ────────────────────────────────────────────────────────────
+
+
+def is_link_like(path):
+    """A symlink, a junction or any reparse point (one lstat), or missing.
+
+    Raises OSError other than "not found" (an unreachable share).
+    """
+    try:
+        info = os.lstat(path)
+    except FileNotFoundError:
+        return False
+    if stat_module.S_ISLNK(info.st_mode):
+        return True
+    attributes = getattr(info, "st_file_attributes", 0)
+    if attributes & FILE_ATTRIBUTE_REPARSE_POINT:
+        return True
+    is_junction = getattr(os.path, "isjunction", None)
+    return bool(is_junction and is_junction(path))
+
+
+# ── source keys ──────────────────────────────────────────────────────
+
+
+def slug(name):
+    """``NFKD`` to ASCII, lower case, runs outside ``[a-z0-9_]`` as ``-``,
+    trimmed and cut to 24 characters; empty becomes ``source``."""
+    text = unicodedata.normalize("NFKD", str(name))
+    text = text.encode("ascii", "ignore").decode("ascii").lower()
+    text = re.sub(r"[^a-z0-9_]+", "-", text).strip("-")
+    text = text[:SLUG_LENGTH].strip("-")
+    return text or "source"
+
+
+def source_key(spelling, identity, taken):
+    """The key of a source: ``slug(basename) + "-" + sha256(identity)[:n]``.
+
+    *taken* maps existing keys to their identity; a key taken by another
+    identity grows its hash to 12, then 16 characters.
+    """
+    base = slug(ntpath.basename(str(spelling).rstrip("\\/")))
+    digest = hashlib.sha256(str(identity).encode("utf-8")).hexdigest()
+    for length in KEY_HASH_LENGTHS:
+        key = f"{base}-{digest[:length]}"
+        owner = taken.get(key)
+        if owner is None or owner == identity:
+            return key
+    raise ValueError("no free source key")
+
+
+def file_identity(path):
+    """``[st_dev, st_ino]`` of an existing folder, or None (no file ids)."""
+    try:
+        info = os.stat(path)
+    except (OSError, ValueError):
+        return None
+    if not info.st_ino:
+        return None
+    return [info.st_dev, info.st_ino]
+
+
+def find_key(keys, spelling, identity, dev_ino):
+    """The marker key of a source: the same configured spelling, then the
+    same identity text, then the same file id; or None."""
+    keys = {k: v for k, v in keys.items() if valid_key(k) and isinstance(v, dict)}
+    for key, entry in keys.items():
+        if entry.get("path") == spelling:
+            return key
+    for key, entry in keys.items():
+        if entry.get("identity") == identity:
+            return key
+    if dev_ino:
+        for key, entry in keys.items():
+            if entry.get("dev_ino") == list(dev_ino):
+                return key
+    return None
+
+
+# ── the marker ───────────────────────────────────────────────────────
+
+
+def marker_path(folder):
+    return os.path.join(folder, MARKER_NAME)
+
+
+def read_marker(folder):
+    """The marker in *folder* as a dict, or None (absent or unreadable as
+    ours). OSError other than "not found" propagates (an unreachable share)."""
+    try:
+        with open(marker_path(folder), "r", encoding="utf-8") as handle:
+            text = handle.read(MAX_MARKER_BYTES + 1)
+    except FileNotFoundError:
+        return None
+    except (ValueError, UnicodeDecodeError):
+        return None
+    if len(text) > MAX_MARKER_BYTES:
+        return None
+    try:
+        data = json.loads(text)
+    except ValueError:
+        return None
+    if not isinstance(data, dict) or not isinstance(data.get("id"), str):
+        return None
+    data["keys"] = valid_keys(data.get("keys"))
+    return data
+
+
+def valid_key(key):
+    """Whether *key* can name a source's folder: one folder name of the
+    ``source_key`` form, never a separator, ``..`` or a drive."""
+    return isinstance(key, str) and KEY_PATTERN.fullmatch(key) is not None
+
+
+def valid_keys(keys):
+    """The marker's keys that are safe to join onto the folder; a hand-edited
+    or foreign entry that is not is dropped (and logged), never followed."""
+    if not isinstance(keys, dict):
+        return {}
+    kept = {}
+    for key, entry in keys.items():
+        if valid_key(key) and isinstance(entry, dict):
+            kept[key] = entry
+        else:
+            logger.warning(
+                "Ignoring a thumbnail folder marker entry that is not a source " "key"
+            )
+    return kept
+
+
+def write_marker(folder, mutate):
+    """Re-read the marker, apply ``mutate(marker)`` and write it atomically
+    (a temp sibling renamed over it). Callers hold ``preview_store.write_lock``.
+    Returns the marker written."""
+    current = read_marker(folder) or {}
+    marker = {
+        "version": MARKER_VERSION,
+        "id": current.get("id"),
+        "created_by_pm": bool(current.get("created_by_pm", False)),
+        "keys": dict(current.get("keys") or {}),
+    }
+    mutate(marker)
+    if not marker.get("id"):
+        raise ValueError("a marker needs an id")
+    target = marker_path(folder)
+    temp = os.path.join(
+        folder, f".{MARKER_NAME}.{os.getpid()}-{threading.get_ident()}.tmp"
+    )
+    try:
+        with open(temp, "w", encoding="utf-8") as handle:
+            json.dump(marker, handle, indent=2, sort_keys=True)
+            handle.flush()
+            os.fsync(handle.fileno())
+        os.replace(temp, target)
+    finally:
+        try:
+            os.unlink(temp)
+        except OSError:
+            pass  # gone with the rename; a leftover is swept with the temps
+    return marker
+
+
+def new_id():
+    return str(uuid.uuid4())
+
+
+def init_folder(folder, *, created_by_pm=False):
+    """The marker id of *folder*: an existing marker is adopted; a folder
+    without one gets a new marker (new id, no keys)."""
+    existing = read_marker(folder)
+    if existing is not None:
+        return existing["id"]
+
+    def create(marker):
+        if not marker.get("id"):
+            marker["id"] = new_id()
+            marker["created_by_pm"] = created_by_pm
+
+    return write_marker(folder, create)["id"]
+
+
+def folder_state(path, expected_id):
+    """``(available, problem, marker)`` of a configured thumbnail folder.
+
+    Available: the folder exists, is a directory and not a link, junction or
+    reparse point, and holds our marker with *expected_id*. Raises OSError
+    when the folder cannot be reached (an I/O error other than not found).
+    """
+    try:
+        info = os.lstat(path)
+    except FileNotFoundError:
+        return False, "missing", None
+    except OSError as error:
+        if error.errno in (errno.ENOENT, errno.ENOTDIR):
+            return False, "missing", None
+        raise
+    if is_link_like(path):
+        return False, "invalid", None
+    if not stat_module.S_ISDIR(info.st_mode):
+        return False, "invalid", None
+    marker = read_marker(path)
+    if marker is None:
+        return False, "missing", None
+    if marker["id"] != expected_id:
+        return False, "marker-mismatch", marker
+    return True, None, marker
+
+
+def holds_only_metadata(path):
+    """Whether an existing folder is empty but for OS metadata files."""
+    with os.scandir(path) as entries:
+        for entry in entries:
+            name = entry.name.lower()
+            if name in OS_METADATA or name.startswith("._"):
+                continue
+            return False
+    return True
+
+
+# ── validation ───────────────────────────────────────────────────────
+
+
+@dataclass(frozen=True)
+class Context:
+    """What a location is checked against (gathered by the caller)."""
+
+    roots: tuple = ()  # every image source of every root list
+    contained: tuple = ()  # ComfyUI output/input/temp and the library folder
+    node_folder: str | None = None
+    default_path: str | None = None
+    current_path: str | None = None  # the folder in use (folder mode)
+    home: str | None = None
+    flavor: object = os.path
+    long_paths: bool | None = None
+    environ: object = None
+    # ComfyUI's folder_paths module (None: none; unset: imported).
+    folder_paths: object = library_location._UNSET
+
+
+def _timed(func, timeout):
+    """``func()`` on a daemon thread; raises TimeoutError past *timeout*.
+    A stuck call is left to finish on its own thread."""
+    result = {}
+    done = threading.Event()
+
+    def run():
+        try:
+            result["value"] = func()
+        except BaseException as error:  # handed to the caller
+            result["error"] = error
+        finally:
+            done.set()
+
+    threading.Thread(target=run, name="pm-preview-stat", daemon=True).start()
+    if not done.wait(timeout):
+        raise TimeoutError("the folder did not answer in time")
+    if "error" in result:
+        raise result["error"]
+    return result.get("value")
+
+
+def _inside(path, folders):
+    return library_location._inside_any(path, folders)
+
+
+def _same(first, second):
+    return library_location.same_folder(first, second) or os.path.normcase(
+        os.path.realpath(first)
+    ) == os.path.normcase(os.path.realpath(second))
+
+
+def _served(path, context):
+    environ = os.environ if context.environ is None else context.environ
+    return (
+        library_location.data_dir_problem(
+            path,
+            folder_paths=context.folder_paths,
+            environ=environ,
+            gallery_roots=list(context.roots),
+        )
+        == "data-dir-served"
+    )
+
+
+def _probe_write(path):
+    """Create and delete a probe file in *path*; False when refused."""
+    probe = os.path.join(path, f".pm-probe-{uuid.uuid4().hex[:8]}.tmp")
+    try:
+        with open(probe, "wb") as handle:
+            handle.write(b"")
+    except OSError:
+        return False
+    try:
+        os.unlink(probe)
+    except OSError:
+        return False
+    return True
+
+
+def location_problem(path, *, purpose, context, timeout=VALIDATION_TIMEOUT):
+    """Why *path* cannot be the thumbnail folder, as a code, or None.
+
+    *purpose*: ``move`` (every rule), ``startup`` (no ``same``, ``empty``,
+    ``writable`` or parent rules: availability covers them) or ``recreate``
+    (the folder is missing and is made again).
+    """
+    flavor = context.flavor
+    code = form_problem(path, flavor=flavor)
+    if code is not None:
+        return code
+    path = flavor.abspath(path)
+    default = bool(context.default_path) and flavor.normcase(path) == flavor.normcase(
+        flavor.abspath(context.default_path)
+    )
+    if is_too_broad(path, home=context.home, flavor=flavor):
+        return "location-too-broad"
+    try:
+        return _timed(
+            lambda: _filesystem_problem(path, purpose, context, default), timeout
+        )
+    except (TimeoutError, OSError):
+        return "location-unavailable"
+
+
+def _filesystem_problem(path, purpose, context, default):
+    if _served(path, context):
+        return "location-served"
+    if context.node_folder and not default and _inside(path, [context.node_folder]):
+        return "location-node-folder"
+    inner = list(context.roots) + list(context.contained)
+    if any(folder and _inside(folder, [path]) for folder in inner):
+        if not default:
+            return "location-contains-source"
+    if (
+        purpose == "move"
+        and context.current_path
+        and (
+            os.path.normcase(path) == os.path.normcase(context.current_path)
+            or (os.path.isdir(path) and _same(path, context.current_path))
+        )
+    ):
+        return "location-same"
+    # Windows, or a test injecting its limit (``long_paths=False``).
+    if os.name == "nt" or context.long_paths is False:
+        if too_long_for_windows(path, context.long_paths):
+            return "location-path-too-long"
+    if purpose == "startup":
+        return None
+    if is_link_like(path):
+        # Never through a link: the folder itself must be a real folder.
+        return "location-not-empty"
+    exists = os.path.isdir(path)
+    if not exists:
+        if os.path.lexists(path):
+            return "location-not-empty"
+        if not default and not os.path.isdir(os.path.dirname(path)):
+            return "location-parent-missing"
+        return None
+    if read_marker(path) is None and not holds_only_metadata(path):
+        return "location-not-empty"
+    if not _probe_write(path):
+        return "location-not-writable"
+    return None

py/api/preview_store.py

@@ -0,0 +1,671 @@
+"""Where previews live on disk (#320): the one resolver.
+
+Every mapping between an image source (a "root"), one of its media files and
+that file's preview on disk goes through this module. URL text stays in
+``thumbnail_settings`` (``thumbnail_rel``: ``thumbnails/<rel>_thumb<ext>``,
+the shape the serve route, ``inspection-state.mjs`` and ``admin.js`` share);
+this module answers where such a preview is on disk.
+
+The store of a source is where its previews live. With the default location
+(mode ``source``, "Inside each source") it is ``<source>/thumbnails``, exactly
+the folder every caller joined by hand before, so nothing moves.
+
+Writes and the switch: every preview writer takes ``write_guard`` when it
+starts (it records the location's ``generation``); the final rename runs
+under ``write_lock`` and only when the generation is unchanged and no hold
+applies (``thumbnail_encode.replace_unless_held``). Changing the location
+bumps the generation under the same lock, so no write that began before can
+land in the old store afterwards. Nothing reads or commits config while
+``write_lock`` is held. The hold check runs under it too, so hold checks take
+no lock (the job registry's ``running()`` is a lock-free snapshot) and
+``bump_generation`` is never called with a registry or config lock held.
+
+All functions are blocking: call them off the event loop.
+"""
+
+import errno
+import logging
+import os
+import threading
+import time
+from contextlib import contextmanager
+from dataclasses import dataclass, replace
+from pathlib import Path
+
+from . import preview_location, thumbnail_settings
+
+try:
+    from ...utils.media_folders import PREVIEW_FOLDER
+except ImportError:  # tests import the package top-level
+    from utils.media_folders import PREVIEW_FOLDER
+
+logger = logging.getLogger("prompt_manager.thumbnails")
+
+SOURCE_MODE = preview_location.SOURCE_MODE
+FOLDER_MODE = preview_location.FOLDER_MODE
+# The probe checks the folder this often, and a check (or a store call)
+# taking longer than the budget marks it unreachable.
+PROBE_INTERVAL = 5.0
+IO_BUDGET = 2.0
+PROBE_THREAD = "pm-preview-probe"
+
+
+@dataclass(frozen=True)
+class Location:
+    """One snapshot of the thumbnail location (take one per request or job)."""
+
+    mode: str = SOURCE_MODE
+    path: str | None = None
+    available: bool = True
+    problem: str | None = None
+    generation: int = 0
+
+
+write_lock = threading.Lock()
+_generation = 0
+# The runtime location: the parsed setting, availability and the marker keys
+# last read. Swapped as a whole; readers take one snapshot.
+_state_lock = threading.Lock()
+_parsed = preview_location.ParsedLocation()
+_available = True
+_problem = None
+_keys = {}
+_key_cache = {}
+_clock = time.monotonic
+
+
+def current():
+    """The thumbnail location now."""
+    with _state_lock:
+        parsed, available, problem, generation_now = (
+            _parsed,
+            _available,
+            _problem,
+            _generation,
+        )
+    if parsed.mode == SOURCE_MODE:
+        return Location(generation=generation_now)
+    return Location(FOLDER_MODE, parsed.path, available, problem, generation_now)
+
+
+def setting():
+    """The parsed setting in use (``preview_location.ParsedLocation``)."""
+    return _parsed
+
+
+def generation():
+    return _generation
+
+
+def bump_generation():
+    """Invalidate every write that started before (under ``write_lock``)."""
+    global _generation
+    with write_lock:
+        _generation += 1
+        return _generation
+
+
+def _canonical(path):
+    """Resolved and case-folded, so paths compare on every OS."""
+    return Path(os.path.normcase(os.path.realpath(str(path))))
+
+
+def _within(path, folder):
+    return _canonical(path).is_relative_to(_canonical(folder))
+
+
+# ── the setting and availability ─────────────────────────────────────
+
+
+def configure(value, *, context=None, check=True):
+    """Use the ``thumbnails.location`` *value* (config.json) from now on.
+
+    A folder location is validated against *context* (``startup`` rules: a
+    problem other than an unreachable folder makes it ``invalid``), then
+    checked once; the probe keeps checking it. Swapped under ``write_lock``
+    with a generation bump, so no write that started before lands.
+    """
+    global _parsed, _available, _problem, _generation
+    parsed = preview_location.parse_location(value)
+    problem = parsed.problem
+    if parsed.mode == FOLDER_MODE and problem is None and context is not None:
+        code = preview_location.location_problem(
+            parsed.path, purpose="startup", context=context
+        )
+        if code == "location-unavailable":
+            problem = "unreachable"
+        elif code is not None:
+            problem = "invalid"
+            parsed = preview_location.ParsedLocation(
+                mode=FOLDER_MODE,
+                path=parsed.path,
+                id=parsed.id,
+                install=parsed.install,
+                cleanup=parsed.cleanup,
+                problem="invalid",
+            )
+    with write_lock:
+        with _state_lock:
+            _parsed = parsed
+            _available = parsed.mode == SOURCE_MODE
+            _problem = problem if parsed.mode == FOLDER_MODE else None
+            _keys.clear()
+            _key_cache.clear()
+        _generation += 1
+    if parsed.mode == FOLDER_MODE:
+        if check and parsed.problem is None:
+            refresh()
+        _probe.start()
+    else:
+        _probe.stop()
+    return current()
+
+
+def refresh():
+    """Check the folder now (bounded by IO_BUDGET); returns availability."""
+    parsed = _parsed
+    if parsed.mode != FOLDER_MODE or parsed.problem is not None:
+        return parsed.mode == SOURCE_MODE
+    try:
+        available, problem, marker = _probe.check(parsed.path, parsed.id)
+    except (OSError, TimeoutError, RuntimeError):
+        available, problem, marker = False, "unreachable", None
+    _set_state(parsed, available, problem, marker)
+    return available
+
+
+def _set_keys(parsed, marker):
+    """Take the keys of a marker just written (availability unchanged)."""
+    with _state_lock:
+        if _parsed is not parsed:
+            return
+        keys = dict((marker or {}).get("keys") or {})
+        if keys != _keys:
+            _keys.clear()
+            _keys.update(keys)
+            _key_cache.clear()
+
+
+def mark_invalid():
+    """The setting cannot be used (a startup check that failed): folder
+    mode stays in force, unavailable, so nothing is written anywhere."""
+    global _parsed, _available, _problem
+    with _state_lock:
+        if _parsed.mode != FOLDER_MODE:
+            _parsed = preview_location.ParsedLocation(
+                mode=FOLDER_MODE, problem="invalid"
+            )
+        else:
+            _parsed = replace(_parsed, problem="invalid")
+        _available, _problem = False, "invalid"
+
+
+def _set_state(parsed, available, problem, marker):
+    global _available, _problem
+    with _state_lock:
+        if _parsed is not parsed:
+            return  # the setting changed meanwhile
+        _available, _problem = available, problem
+        keys = dict((marker or {}).get("keys") or {})
+        if keys != _keys:
+            _keys.clear()
+            _keys.update(keys)
+            _key_cache.clear()
+
+
+def note_failure():
+    """A store call failed or stalled: unreachable until the probe finds the
+    folder again (requests do no store I/O meanwhile)."""
+    global _available, _problem
+    if _parsed.mode != FOLDER_MODE:
+        return
+    with _state_lock:
+        _available, _problem = False, "unreachable"
+    _probe.wake()
+
+
+@contextmanager
+def store_io():
+    """Around a store call in folder mode: an I/O error (other than a file
+    that is not there) or a call over IO_BUDGET marks the folder
+    unreachable."""
+    if _parsed.mode != FOLDER_MODE:
+        yield
+        return
+    started = _clock()
+    try:
+        yield
+    except OSError as error:
+        if not isinstance(error, (FileNotFoundError, NotADirectoryError)):
+            note_failure()
+        raise
+    finally:
+        if _clock() - started > IO_BUDGET:
+            note_failure()
+
+
+class _Probe:
+    """The background check of the thumbnail folder (one thread, one check
+    at a time; a stuck check is left to finish on its own thread)."""
+
+    def __init__(self):
+        self._lock = threading.Lock()
+        self._wake = threading.Event()
+        self._stop = threading.Event()
+        self._thread = None
+        self._checking = None
+
+    def check(self, path, expected_id):
+        """``folder_state`` within IO_BUDGET; raises TimeoutError. A check
+        already running (the probe's, or a stuck one) is joined, never run
+        twice at once."""
+        with self._lock:
+            pending = self._checking
+            if pending is None or pending[0] != (path, expected_id):
+                pending = self._start_check(path, expected_id)
+        key, done, result = pending
+        if not done.wait(IO_BUDGET):
+            raise TimeoutError("the thumbnail folder did not answer in time")
+        with self._lock:
+            if self._checking is pending:
+                self._checking = None
+        if "error" in result:
+            raise result["error"]
+        return result["value"]
+
+    def _start_check(self, path, expected_id):
+        """Start one check on its own thread (lock held)."""
+        result = {}
+        done = threading.Event()
+
+        def run():
+            try:
+                result["value"] = preview_location.folder_state(path, expected_id)
+            except BaseException as error:  # handed to the caller
+                result["error"] = error
+            finally:
+                done.set()
+
+        pending = ((path, expected_id), done, result)
+        self._checking = pending
+        threading.Thread(target=run, name=PROBE_THREAD + "-check", daemon=True).start()
+        return pending
+
+    def start(self):
+        with self._lock:
+            if self._thread is not None and self._thread.is_alive():
+                return
+            # Each thread has its own stop: a stopped one never resumes.
+            stop = self._stop = threading.Event()
+            thread = threading.Thread(
+                target=self._run, args=(stop,), name=PROBE_THREAD, daemon=True
+            )
+            try:
+                thread.start()
+            except RuntimeError:
+                return  # refused at interpreter exit: no probe
+            self._thread = thread
+
+    def _run(self, stop):
+        while not stop.is_set():
+            self._wake.wait(PROBE_INTERVAL)
+            self._wake.clear()
+            if stop.is_set():
+                return
+            try:
+                refresh()
+            except Exception:  # one failed check never stops the probe
+                logger.debug("Thumbnail folder check failed", exc_info=True)
+
+    def wake(self):
+        self._wake.set()
+
+    def stop(self, timeout=2.0):
+        """Stop the probe; True when its thread ended."""
+        with self._lock:
+            thread, self._thread = self._thread, None
+        self._stop.set()
+        self._wake.set()
+        if thread is None or thread is threading.current_thread():
+            return True
+        thread.join(timeout)
+        return not thread.is_alive()
+
+
+_probe = _Probe()
+
+
+def stop_probe(timeout=2.0):
+    """Stop the folder probe (the package teardown, tests)."""
+    return _probe.stop(timeout)
+
+
+# ── stores ───────────────────────────────────────────────────────────
+
+
+def source_folder(root):
+    """``<source>/thumbnails``: the store in source mode, a leftover in
+    folder mode."""
+    return Path(root) / PREVIEW_FOLDER
+
+
+def store_container(root, location=None):
+    """The folder a store of *root* must stay inside: the source itself, or
+    the thumbnail folder in folder mode."""
+    location = location or current()
+    if location.mode == FOLDER_MODE:
+        return Path(location.path) if location.path else None
+    return Path(root)
+
+
+def _identity(root):
+    return os.path.normcase(os.path.realpath(str(root)))
+
+
+def _lookup_key(root):
+    spelling = str(root)
+    with _state_lock:
+        if spelling in _key_cache:
+            return _key_cache[spelling]
+        keys = dict(_keys)
+    key = preview_location.find_key(
+        keys,
+        spelling,
+        _identity(root),
+        preview_location.file_identity(root),
+    )
+    if key is not None:
+        with _state_lock:
+            _key_cache[spelling] = key
+    return key
+
+
+def store_dir(root, location=None):
+    """The store of *root*: ``<source>/thumbnails``, or in folder mode
+    ``<folder>/<key>`` (None while the folder is unavailable or before the
+    source has a key: a reader then finds no preview)."""
+    location = location or current()
+    if location.mode == SOURCE_MODE:
+        return Path(root) / PREVIEW_FOLDER
+    if not location.available or not location.path:
+        return None
+    key = _lookup_key(root)
+    return None if key is None else _key_folder(location.path, key)
+
+
+def _key_folder(folder, key):
+    """``<folder>/<key>``, only for a key that is one folder name directly
+    below the thumbnail folder (a marker is data, never a path)."""
+    if not preview_location.valid_key(key):
+        return None
+    store = Path(folder) / key
+    if store.parent != Path(folder) or store.name != key:
+        return None
+    return store
+
+
+def ensure_store(root, location=None, *, create=False):
+    """``store_dir`` for a writer: in folder mode a source without a key gets
+    one (recorded in the marker); with *create* its key folder is made (never
+    the thumbnail folder itself). None while the folder is unavailable."""
+    location = location or current()
+    store = store_dir(root, location)
+    if location.mode == SOURCE_MODE or (store is None and not location.available):
+        return store
+    if store is None:
+        store = _assign_key(root, location)
+        if store is None:
+            return None
+    if create:
+        try:
+            with store_io():
+                os.mkdir(store)
+        except FileExistsError:
+            pass
+        except OSError:
+            return None
+    return store
+
+
+def _assign_key(root, location):
+    parsed = _parsed
+    if location.path != parsed.path:
+        return None
+    spelling = str(root)
+    identity = _identity(root)
+    dev_ino = preview_location.file_identity(root)
+    assigned = {}
+
+    def add(marker):
+        if marker.get("id") != parsed.id:
+            raise ValueError("another folder's marker")  # marker-mismatch
+        keys = marker["keys"]
+        key = preview_location.find_key(keys, spelling, identity, dev_ino)
+        if key is None:
+            taken = {k: v.get("identity") for k, v in keys.items()}
+            key = preview_location.source_key(spelling, identity, taken)
+            keys[key] = {
+                "path": spelling,
+                "identity": identity,
+                "dev_ino": dev_ino,
+                "install": parsed.install,
+            }
+        assigned["key"] = key
+
+    try:
+        with write_lock, store_io():
+            marker = preview_location.write_marker(location.path, add)
+    except (OSError, ValueError):
+        return None
+    _set_keys(parsed, marker)
+    return _key_folder(location.path, assigned["key"])
+
+
+def may_write(path, location=None):
+    """The one ownership check every preview write and delete passes.
+
+    Source mode: True (the callers' own root rules apply, as before). Folder
+    mode: *path* lies below a source key folder of the thumbnail folder,
+    lexically and resolved, and no link, junction or reparse point sits
+    anywhere from the key folder down to it (the file itself included).
+    """
+    location = location or current()
+    if location.mode == SOURCE_MODE:
+        return True
+    if not location.path:
+        return False
+    folder = Path(os.path.abspath(location.path))
+    path = Path(os.path.abspath(path))
+    try:
+        relative = path.relative_to(folder)
+    except ValueError:
+        return False
+    if len(relative.parts) < 2 or ".." in relative.parts:
+        return False
+    store = _key_folder(folder, relative.parts[0])
+    if store is None or not _within(path, folder):
+        return False
+    try:
+        return _no_link_below(store, path)
+    except OSError:
+        note_failure()
+        return False
+
+
+def make_parent(dst, location=None):
+    """Make the folders a preview *dst* is written into. In folder mode only
+    folders below the thumbnail folder are made, never the folder itself,
+    and only while it holds this install's marker (an unplugged drive or an
+    unmounted mount point raises FileNotFoundError); a *dst* that does not
+    pass ``may_write`` raises PermissionError."""
+    location = location or current()
+    dst = Path(dst)
+    if location.mode == SOURCE_MODE or not location.path:
+        if location.mode != SOURCE_MODE:
+            raise FileNotFoundError(errno.ENOENT, "thumbnail folder unavailable")
+        dst.parent.mkdir(parents=True, exist_ok=True)
+        return
+    folder = Path(os.path.abspath(location.path))
+    with store_io():
+        if not location.available or not folder.is_dir():
+            raise FileNotFoundError(errno.ENOENT, "thumbnail folder unavailable")
+        marker = preview_location.read_marker(str(folder))
+        if marker is None or marker.get("id") != _parsed.id:
+            note_failure()
+            raise FileNotFoundError(errno.ENOENT, "thumbnail folder unavailable")
+        if not may_write(dst, location):
+            raise PermissionError(errno.EACCES, "outside the thumbnail folder")
+        current_folder = folder
+        for part in Path(os.path.abspath(dst.parent)).relative_to(folder).parts:
+            current_folder = current_folder / part
+            try:
+                os.mkdir(current_folder)
+            except FileExistsError:
+                pass
+            if preview_location.is_link_like(current_folder):
+                raise PermissionError(errno.EACCES, "a link in the thumbnail folder")
+
+
+def store_is_link(store, location=None):
+    """Whether a store folder is a link (a junction or reparse point too in
+    folder mode): it is skipped by sweeps and refused by clears."""
+    location = location or current()
+    if location.mode == SOURCE_MODE:
+        return Path(store).is_symlink()
+    return preview_location.is_link_like(store)
+
+
+def given_store(root, store):
+    """A caller's explicit store argument: the default spelling
+    (``<root>/thumbnails``) means the resolver's store; another folder (only
+    tests pass one) is used as given."""
+    store = Path(store)
+    if store == Path(root) / PREVIEW_FOLDER:
+        return store_dir(root)
+    return store
+
+
+def preview_path(root, media_rel, ext=None, location=None, *, create=False):
+    """Where the preview of *media_rel* (relative to *root*) is, or is to be
+    written (*create*: a writer, which gives a new source its key), in *ext*
+    (the extension written now when None)."""
+    if create:
+        store = ensure_store(root, location)
+    else:
+        store = store_dir(root, location)
+    if store is None:
+        return None
+    if ext is None:
+        from .thumbnail_encode import writer_settings
+
+        ext = writer_settings().extension
+    return store / (thumbnail_settings.preview_stem(media_rel) + ext)
+
+
+def request_path(root, parts, location=None):
+    """The disk path of the URL parts ``("thumbnails", ...)``, or None when
+    *parts* is not under an exact ``thumbnails`` first part or the store has
+    no place for it. The text is checked before (``is_preview_text``)."""
+    parts = tuple(parts)
+    if len(parts) < 2 or parts[0] != PREVIEW_FOLDER:
+        return None
+    store = store_dir(root, location)
+    if store is None:
+        return None
+    return store.joinpath(*parts[1:])
+
+
+def _no_link_below(store, path):
+    """No folder from *store* down to *path* (and *store* itself) is a link,
+    junction or reparse point (lexical walk, one lstat each)."""
+    store = Path(os.path.abspath(store))
+    path = Path(os.path.abspath(path))
+    try:
+        relative = path.relative_to(store)
+    except ValueError:
+        return False
+    current = store
+    for part in ("",) + relative.parts:
+        current = current / part if part else current
+        if preview_location.is_link_like(current):
+            return False
+    return True
+
+
+def owns(root, path, location=None):
+    """Whether *path* lies inside the store of *root*, resolved: the store
+    stays inside its container and no link takes *path* out of the store.
+    In folder mode no link, junction or reparse point may sit anywhere from
+    the store down to *path*."""
+    location = location or current()
+    store = store_dir(root, location)
+    if store is None:
+        return False
+    container = store_container(root, location)
+    if not (_within(store, container) and _within(path, store)):
+        return False
+    if location.mode == SOURCE_MODE:
+        return True
+    return may_write(path, location)
+
+
+# ── preview text ─────────────────────────────────────────────────────
+
+
+def is_preview_text(filepath):
+    """URL text naming a preview: ``thumbnails/<...>/<name>_thumb<ext>``.
+
+    Text only, before any join: no backslash, drive or stream colon, and no
+    empty, ``.`` or ``..`` segment; ``thumbnails`` exactly as the first part
+    and nowhere else among the folders; the extension, in any case, one a
+    preview may carry (``X_thumb.JPG`` of an older release included).
+    """
+    if not filepath or "\\" in filepath or ":" in filepath:
+        return False
+    parts = filepath.split("/")
+    if len(parts) < 2 or parts[0] != PREVIEW_FOLDER:
+        return False
+    if any(part in ("", ".", "..") for part in parts):
+        return False
+    if PREVIEW_FOLDER in parts[1:-1]:
+        return False
+    stem, extension = os.path.splitext(parts[-1])
+    return (
+        stem.endswith(thumbnail_settings.THUMB_SUFFIX)
+        and len(stem) > len(thumbnail_settings.THUMB_SUFFIX)
+        and extension.lower() in thumbnail_settings.THUMBNAIL_EXTENSIONS
+    )
+
+
+# ── writes ───────────────────────────────────────────────────────────
+
+
+class _WriteGuard:
+    """``guard()`` for one preview write: true while the location has not
+    changed since the write started and *hold* (if any) allows it."""
+
+    __slots__ = ("generation", "_hold")
+
+    def __init__(self, hold=None):
+        self.generation = _generation
+        self._hold = hold
+
+    def __call__(self):
+        if self.generation != _generation:
+            return False
+        return self._hold is None or bool(self._hold())
+
+
+def write_guard(hold=None):
+    """Take when a preview write starts; hand to its final rename."""
+    if isinstance(hold, _WriteGuard):
+        return hold
+    return _WriteGuard(hold)
+
+
+@contextmanager
+def committed(guard=None):
+    """Around a preview's final rename: holds ``write_lock`` and yields
+    whether the write may land (``guard()``, re-checked under the lock)."""
+    with write_lock:
+        yield guard is None or bool(guard())

py/api/settings_routes.py

@@ -30,6 +30,7 @@ from . import thumbnail_settings
 from .admin import _current_image_monitor
 from .job_routes import busy_response
 from .jobs import THUMBNAILS_JOB_KIND, JobBusy
+from .thumbnail_location import needs_move_response
 
 try:
     from ...utils.validators import validate_result_timeout, validate_worker_threads
@@ -264,6 +265,12 @@ class SettingsRoutesMixin:
                     "sources": source_status,
                     "monitor": monitor,
                     "thumbnail_encoders": encoders,
+                    # #320: the full path only here (D6A).
+                    "thumbnail_location": await self._run_in_executor(
+                        functools.partial(
+                            self._thumbnail_location_payload, with_path=True
+                        )
+                    ),
                     "settings": {
                         "monitoring_enabled": GalleryConfig.MONITORING_ENABLED,
                         "save_foreign_runs": GalleryConfig.SAVE_FOREIGN_RUNS,
@@ -377,6 +384,9 @@ class SettingsRoutesMixin:
             if error_response is not None:
                 return error_response
 
+            if "thumbnail_location" in data:
+                # #320: only the Move thumbnails job changes the location.
+                return needs_move_response()
             expected_revision = data.get("expected_revision")
             if expected_revision is not None and not isinstance(expected_revision, str):
                 return web.json_response(

py/api/sources.py

@@ -30,6 +30,8 @@ import ntpath
 import os
 import re
 
+from .preview_location import HOLDS_THUMBNAILS_REASON
+
 logger = logging.getLogger("prompt_manager.api")
 
 MAX_SOURCE_PATH = 4096  # characters
@@ -114,7 +116,26 @@ def source_problem(text):
     code = source_form_error(text)
     if code is not None:
         return code, FORM_REASONS[code]
-    return GalleryConfig.gallery_root_problem(text)
+    code, reason = GalleryConfig.gallery_root_problem(text)
+    if code is None and _holds_thumbnails(GalleryConfig.resolve_gallery_root(text)):
+        return "holds-thumbnails", HOLDS_THUMBNAILS_REASON
+    return code, reason
+
+
+def _holds_thumbnails(path):
+    """Whether *path* is inside or around the thumbnail folder in use (#320):
+    a source there would list Prompt Manager's own previews."""
+    from . import preview_store
+
+    try:
+        from ...utils.library_location import _inside_any
+    except ImportError:  # tests import the package top-level
+        from utils.library_location import _inside_any
+
+    setting = preview_store.setting()
+    if setting.mode != preview_store.FOLDER_MODE or not setting.path:
+        return False
+    return _inside_any(path, [setting.path]) or _inside_any(setting.path, [path])
 
 
 def public_spelling(text):

py/api/thumbnail_auto.py

@@ -8,7 +8,8 @@ previews behind those URLs are made here, in three ways:
 - **On first view.** ``GET /prompt_manager/images/serve/thumbnails/<rel>_thumb
   <ext>`` for a preview that does not exist yet is admitted on the event loop
   (``_PreviewGate``): at most ``ON_DEMAND_LIMIT`` previews are written at once,
-  on this API's own small pool (never the default executor), one flight runs
+  on this API's interactive image pool (``IMAGE_POOL_SIZE`` threads, shared
+  with card facts and inspector reads; never the default executor), one flight runs
   per file, and the requests waiting are capped (``MAX_WAITING``); past the
   cap a request gets its fallback at once. Inside the admission the preview is
   mapped back to its media file under the same root (the request text is
@@ -24,7 +25,8 @@ previews behind those URLs are made here, in three ways:
 - **On capture.** The image monitor hands every new output it settles to
   ``queue_capture_thumbnail``, which queues its preview for one background
   worker thread (``AutoThumbnailer``). Each wake takes at most Worker threads
-  (``WORKER_THREADS``) files and writes them on that many threads; enqueuing
+  (``WORKER_THREADS``) files and writes them on the long-lived job pool
+  (``utils.parallel``, shared with scans and thumbnail jobs); enqueuing
   is O(1), so the monitor and ComfyUI's queue never wait. A file already
   queued is not queued again, the queue is bounded (``MAX_QUEUED``) and a
   preview left out is made on its first view instead.
@@ -49,7 +51,7 @@ write starts (after its slot) and again just before its rename.
 
 Shutdown: ``close_auto_thumbnails`` stops the worker at a file boundary,
 kills a running ffmpeg, waits a bounded time (and logs when the wait ran
-out) and shuts the view pool down; after the app's cleanup
+out) and shuts the image pool down; after the app's cleanup
 (``final=True``) nothing starts a worker again. Importing this module again
 (a package reload) stops the workers the previous import left.
 """
@@ -60,12 +62,12 @@ import functools
 import io
 import os
 import threading
-from concurrent.futures import ThreadPoolExecutor
+from concurrent.futures import CancelledError, ThreadPoolExecutor
 from pathlib import Path
 
 from aiohttp import web
 
-from . import thumbnail_settings
+from . import preview_store, thumbnail_settings
 from .images import (
     in_trash_below_roots,
     MEDIA_EXTENSIONS,
@@ -76,7 +78,7 @@ from .images import (
     _thumbnail_is_fresh,
     _video_placeholder_image,
     _worker_threads,
-    media_thumbnail_rel,
+    media_preview_path,
 )
 from .jobs import (
     DUPLICATE_CLEANUP_JOB_KIND,
@@ -104,8 +106,11 @@ PLACEHOLDER_SIZE = (thumbnail_settings.DEFAULT_EDGE, thumbnail_settings.DEFAULT_
 PLACEHOLDER_QUALITY = 85
 # Source extensions in the order a shared preview name looks for them (R2).
 _SOURCE_ORDER = thumbnail_settings.IMAGE_SOURCE_ORDER + tuple(sorted(VIDEO_EXTENSIONS))
-# Previews views may write at once (the size of the view pool).
-ON_DEMAND_LIMIT = 3
+# Threads of the interactive image pool (#523): view previews, card facts and
+# inspector reads. Fixed, so image buffers stay in a few threads' arenas.
+IMAGE_POOL_SIZE = 3
+# Previews views may write at once (the whole image pool).
+ON_DEMAND_LIMIT = IMAGE_POOL_SIZE
 # View requests that may wait on the gate; one more gets its fallback at once.
 MAX_WAITING = 64
 # How long a pool thread waits for the capture worker's flight of the same file.
@@ -124,7 +129,7 @@ AUTO_REFUSED_KINDS = frozenset(
     {RESTORE_JOB_KIND, DUPLICATE_CLEANUP_JOB_KIND, SOURCE_CHANGE_JOB_KIND}
 )
 WORKER_NAME = "PromptManagerThumbnailWorker"
-POOL_PREFIX = "pm-preview"
+POOL_PREFIX = "pm-image"
 # Identifies this import's workers: a reload stops the ones it did not start.
 _MODULE_TOKEN = object()
 
@@ -153,6 +158,36 @@ def _dst_key(dst):
     return flight_key(Path(dst).parent, (Path(dst).name,))
 
 
+class DeferredPreview:
+    """The preview of *rel* under *root*, resolved when its write starts
+    (#320): a queued capture follows the thumbnail location at write time,
+    not the one when it was queued."""
+
+    __slots__ = ("root", "rel", "strict")
+
+    def __init__(self, root, rel, *, strict=True):
+        self.root = Path(root)
+        self.rel = Path(rel)
+        # A capture refuses a store linked out of its container (the serve
+        # route's rule); a planned target keeps the plan's rule: inside the
+        # store, as the thumbnail job writes it.
+        self.strict = strict
+
+    def resolve(self):
+        """The preview's path now, or None when nothing may be written."""
+        dst = media_preview_path(self.root, self.rel, create=True)
+        if dst is None:
+            return None
+        if self.strict:
+            return dst if preview_store.owns(self.root, dst) else None
+        store = preview_store.store_dir(self.root)
+        return dst if _is_within(dst, store) else None
+
+
+def _resolved(dst):
+    return dst.resolve() if isinstance(dst, DeferredPreview) else Path(dst)
+
+
 @functools.lru_cache(maxsize=1)
 def video_placeholder_jpeg():
     """The placeholder frame as JPEG bytes (a video whose preview is missing)."""
@@ -210,10 +245,19 @@ def _candidates(parts):
 def _current_preview(root, parts):
     """The preview *parts* names, in the format written now (#317): a request
     for an older name (``_thumb.png`` before a conversion) is answered with
-    the current file."""
+    the current file. None when the store of *root* has no place for it."""
     _folder, base, _wanted = _candidates(parts)
     name = base + thumbnail_settings.THUMB_SUFFIX + writer_settings().extension
-    return Path(root).joinpath(*parts[:-1], name)
+    return preview_store.request_path(root, (*parts[:-1], name))
+
+
+def _request_key(root, parts):
+    """The flight key of the preview *parts* under *root*: the key of its
+    disk path (so the serve and history routes share one flight)."""
+    path = preview_store.request_path(root, parts)
+    if path is None:
+        return flight_key(root, parts)
+    return _dst_key(path)
 
 
 def _quick_source(root, parts):
@@ -254,12 +298,14 @@ def _thumbnail_source(root, parts):
     if in_trash_below_roots(found, [root]):
         return None
     rel = Path(*folder_parts, found.name)
-    dst = root / media_thumbnail_rel(rel)
+    dst = media_preview_path(root, rel, create=True)
+    if dst is None:
+        # Nowhere to write (the thumbnail folder is unavailable): the
+        # original is served and nothing is written.
+        return found, None, found.suffix.lower() in VIDEO_EXTENSIONS
     if dst != _current_preview(root, parts):
         return None
-    if not _is_within(root / "thumbnails", root) or not _is_within(
-        dst, root / "thumbnails"
-    ):
+    if not preview_store.owns(root, dst):
         dst = None
     return found, dst, found.suffix.lower() in VIDEO_EXTENSIONS
 
@@ -279,6 +325,21 @@ def _scan_folder(folder, base, extensions):
     return None
 
 
+def _deferred(roots, src, dst):
+    """The ``DeferredPreview`` of a planned ``(src, dst)``: the root whose
+    store the plan wrote *dst* into (nested roots plan one each); *dst* as
+    planned when none matches."""
+    src = Path(src)
+    for root in roots:
+        root = Path(root)
+        if not src.is_relative_to(root):
+            continue
+        rel = src.relative_to(root)
+        if media_preview_path(root, rel) == Path(dst):
+            return DeferredPreview(root, rel, strict=False)
+    return dst
+
+
 def _stop_stale_workers():
     """Stop capture workers a previous import of this module started."""
     for thread in threading.enumerate():
@@ -294,7 +355,7 @@ class AutoThumbnailer:
     ``generate(src, dst, is_video, *, stop, guard, track)`` writes one
     preview and returns ``_generate_one``'s result dict; ``may_write()``
     says whether automatic previews may be written now. Views call
-    ``ensure`` on the view pool, the monitor calls ``enqueue`` from its
+    ``ensure`` on the image pool, the monitor calls ``enqueue`` from its
     thread.
     """
 
@@ -420,16 +481,23 @@ class AutoThumbnailer:
 
     def enqueue(self, src, dst, is_video):
         """Queue *dst*'s preview for the worker; False when already queued,
-        full, closed or its worker is refused at interpreter exit. Never
-        blocks on a write."""
-        key = _dst_key(dst)
+        full, closed, nowhere to write it or its worker is refused at
+        interpreter exit. Never blocks on a write. *dst* may be a
+        ``DeferredPreview``: its path is resolved again when the write
+        starts."""
+        now = _resolved(dst)
+        if now is None:
+            return False
+        key = _dst_key(now)
+        if not isinstance(dst, DeferredPreview):
+            dst = now
         with self._changed:
             if self._closed or key in self._queued:
                 return False
             if len(self._queue) >= self._max_queued:
                 return False
             self._queued.add(key)
-            self._queue.append((key, Path(src), Path(dst), bool(is_video)))
+            self._queue.append((key, Path(src), dst, bool(is_video)))
             self._busy = True
             started = True
             if self._start_worker and not self._worker_running:
@@ -491,12 +559,15 @@ class AutoThumbnailer:
                     self._worker_running = False
                     self._changed.notify_all()
                     return
-                take = min(len(self._queue), max(1, int(self._workers() or 1)))
+                workers = max(1, int(self._workers() or 1))
+                take = min(len(self._queue), workers)
                 batch = [self._queue.popleft() for _ in range(take)]
                 self._batch = len(batch)
                 self._changed.notify_all()
             try:
-                map_parallel(self._write_queued, batch, len(batch))
+                # The job pool's size is the setting; a smaller batch uses
+                # fewer of its threads (#523: one long-lived pool).
+                map_parallel(self._write_queued, batch, workers)
             finally:
                 with self._changed:
                     self._batch = 0
@@ -506,6 +577,9 @@ class AutoThumbnailer:
     def _write_queued(self, item):
         _key, src, dst, is_video = item
         try:
+            dst = _resolved(dst)
+            if dst is None:
+                return  # nowhere to write it now: made on its first view
             self.ensure(src, dst, is_video)
         except Exception:  # one file never stops the worker
             self._logger.warning(
@@ -533,6 +607,7 @@ class AutoThumbnailer:
             try:
                 process.kill()
             except OSError:
+                # the process has already exited
                 pass
         if worker is None:
             return True
@@ -566,7 +641,7 @@ class _PreviewGate:
     """Admission of view requests on the event loop (#249 I2).
 
     Waiters are coroutines: at most ``limit`` previews are written at once
-    on the view pool, one flight runs per key, and past ``MAX_WAITING``
+    on the image pool, one flight runs per key, and past ``MAX_WAITING``
     waiting requests ``run`` answers ``OVER`` at once.
     """
 
@@ -621,13 +696,17 @@ class _PreviewGate:
                 flight.set_result(result)
 
 
+def _on_image_thread():
+    return threading.current_thread().name.startswith(POOL_PREFIX + "_")
+
+
 class AutoThumbnailMixin:
     """Automatic previews on the API: views, the monitor's queue, scans."""
 
     _auto_thumbnailer = None
     _auto_thumbnails_shut = False
     _preview_gate_obj = None
-    _preview_pool_obj = None
+    _image_pool_obj = None
     _auto_thumbnailer_lock = threading.Lock()
 
     def _auto_thumbnails(self):
@@ -650,7 +729,7 @@ class AutoThumbnailMixin:
             self._auto_thumbnails_shut = True
 
     def close_auto_thumbnails(self, final=False, timeout=None):
-        """Stop the capture worker and the view pool, and forget them.
+        """Stop the capture worker and the image pool, and forget them.
 
         Bounded by ``timeout`` (see AutoThumbnailer.close). ``final`` (the
         package teardown) also keeps a late monitor event from starting a
@@ -661,7 +740,7 @@ class AutoThumbnailMixin:
             if final:
                 self._auto_thumbnails_shut = True
             thumbnailer, self._auto_thumbnailer = self._auto_thumbnailer, None
-            pool, self._preview_pool_obj = self._preview_pool_obj, None
+            pool, self._image_pool_obj = self._image_pool_obj, None
             self._preview_gate_obj = None
         closed = True
         if thumbnailer is not None:
@@ -670,6 +749,8 @@ class AutoThumbnailMixin:
             pool.shutdown(wait=False, cancel_futures=True)
         if final:
             shutdown_encoders()  # kill JPEG XL / ffmpeg encoders still running
+            # The thumbnail folder's probe (#320), bounded like the rest.
+            closed = preview_store.stop_probe() and closed
         return closed
 
     def _auto_thumbnail_failures(self):
@@ -705,16 +786,67 @@ class AutoThumbnailMixin:
             gate = self._preview_gate_obj = _PreviewGate(ON_DEMAND_LIMIT, self.logger)
         return gate
 
-    def _preview_pool(self):
-        with AutoThumbnailMixin._auto_thumbnailer_lock:
-            if self._preview_pool_obj is None:
-                self._preview_pool_obj = ThreadPoolExecutor(
-                    ON_DEMAND_LIMIT, thread_name_prefix=POOL_PREFIX
-                )
-            return self._preview_pool_obj
+    def _image_pool(self):
+        """The interactive image pool (#523): IMAGE_POOL_SIZE threads for view
+        previews (behind their gate), card facts and inspector reads, so
+        image buffers never spread over the default executor's threads.
 
-    def _preview_pool_threads(self):
-        pool = self._preview_pool_obj
+        None after the package teardown (``close_auto_thumbnails(final=True)``):
+        a late request then runs on the default executor (``run_in_executor``
+        with None) and starts no thread the teardown no longer stops.
+        """
+        with AutoThumbnailMixin._auto_thumbnailer_lock:
+            if self._image_pool_obj is None and not self._auto_thumbnails_shut:
+                self._image_pool_obj = ThreadPoolExecutor(
+                    IMAGE_POOL_SIZE, thread_name_prefix=POOL_PREFIX
+                )
+            return self._image_pool_obj
+
+    async def _run_image(self, func, *args, **kwargs):
+        """``_run_in_executor`` for interactive image work: the image pool.
+
+        After the teardown, or with the pool shut down in between (a test
+        reset), the call runs on the default executor as before.
+        """
+        call = functools.partial(func, *args, **kwargs)
+        loop = asyncio.get_running_loop()
+        try:
+            future = loop.run_in_executor(self._image_pool(), call)
+        except RuntimeError:  # submit refused: the pool was shut down
+            future = loop.run_in_executor(None, call)
+        return await future
+
+    def _map_image(self, func, items):
+        """``func`` over *items* on the image pool, in order (blocking).
+
+        Called from an image pool thread, after the teardown, or with the
+        pool shut down in between (its queued items are cancelled), the
+        items it did not run run on the calling thread.
+        """
+        items = list(items)
+        pool = None if not items or _on_image_thread() else self._image_pool()
+        if pool is None:
+            return [func(item) for item in items]
+        futures = []
+        try:
+            for item in items:
+                futures.append(pool.submit(func, item))
+        except RuntimeError:
+            pass  # shut down in between: the rest run here
+        results = []
+        for index, item in enumerate(items):
+            future = futures[index] if index < len(futures) else None
+            if future is None or future.cancelled():
+                results.append(func(item))
+                continue
+            try:
+                results.append(future.result())
+            except CancelledError:  # cancelled while this caller waited
+                results.append(func(item))
+        return results
+
+    def _image_pool_threads(self):
+        pool = self._image_pool_obj
         return [] if pool is None else list(getattr(pool, "_threads", ()))
 
     def _video_placeholder_bytes(self):
@@ -729,7 +861,7 @@ class AutoThumbnailMixin:
         return await self._preview_gate().run(
             flight_key(Path(dst).parent, (Path(dst).name,)),
             functools.partial(self._ensure_view, src, dst, is_video),
-            self._preview_pool(),
+            self._image_pool(),
         )
 
     def _ensure_view(self, src, dst, is_video):
@@ -773,17 +905,17 @@ class AutoThumbnailMixin:
         The flight answers only the outcome (a history flight may be the one
         joined); the file it previews is derived here: the preview path is
         the request's own, and a fallback looks its source up again on the
-        view pool (bounded by it, never the default executor).
+        image pool (bounded by it, never the default executor).
         """
         if _has_traversal(filepath) or not _is_preview_request(filepath):
             return None
         parts = tuple(filepath.split("/"))
         gate = self._preview_gate()
-        pool = self._preview_pool()
+        pool = self._image_pool()
         for root in output_dirs:
             root = Path(root)
             outcome = await gate.run(
-                flight_key(root, parts),
+                _request_key(root, parts),
                 functools.partial(self._preview_on_demand, root, parts),
                 pool,
             )
@@ -796,7 +928,7 @@ class AutoThumbnailMixin:
                     continue
                 return self._preview_response(BUSY, quick[0], None, quick[1])
             dst = _current_preview(root, parts)
-            if outcome == READY:
+            if outcome == READY and dst is not None:
                 return self._file_response(dst)
             located = await gate.loop.run_in_executor(
                 pool, _thumbnail_source, root, parts
@@ -819,17 +951,31 @@ class AutoThumbnailMixin:
         """
         if self._auto_thumbnails_shut:
             return "skipped"
-        located = self._capture_target(image_path)
+        located = self._capture_source(image_path)
         if located is None:
             return "skipped"
-        src, dst, is_video = located
+        src, root, rel, is_video = located
+        dst = DeferredPreview(root, rel).resolve()
+        if dst is None:
+            return "skipped"
         if _thumbnail_is_fresh(src, dst):
             return "fresh"
-        if self._auto_thumbnails().enqueue(src, dst, is_video):
+        if self._auto_thumbnails().enqueue(src, DeferredPreview(root, rel), is_video):
             return "queued"
         return "skipped"
 
     def _capture_target(self, image_path):
+        """``(src, dst, is_video)`` of a new output's preview now, or None."""
+        located = self._capture_source(image_path)
+        if located is None:
+            return None
+        src, root, rel, is_video = located
+        dst = DeferredPreview(root, rel).resolve()
+        return None if dst is None else (src, dst, is_video)
+
+    def _capture_source(self, image_path):
+        """``(src, root, rel, is_video)`` of a media file under a current
+        root (not a preview, a link or in a trash folder), or None."""
         path = Path(os.path.abspath(str(image_path)))
         if path.suffix.lower() not in MEDIA_EXTENSIONS or not _regular_file(path):
             return None
@@ -842,12 +988,7 @@ class AutoThumbnailMixin:
             rel = Path(os.path.relpath(path, root))
             if "thumbnails" in rel.parts[:-1] or in_trash_below_roots(path, [root]):
                 return None
-            dst = root / media_thumbnail_rel(rel)
-            if not _is_within(root / "thumbnails", root) or not _is_within(
-                dst, root / "thumbnails"
-            ):
-                return None
-            return path, dst, path.suffix.lower() in VIDEO_EXTENSIONS
+            return path, root, rel, path.suffix.lower() in VIDEO_EXTENSIONS
         return None
 
     # ── after a scan ──────────────────────────────────────────────────
@@ -889,7 +1030,7 @@ class AutoThumbnailMixin:
             return "none"
         thumbnailer = self._auto_thumbnails()
         for src, dst, is_video in plan["targets"]:
-            thumbnailer.enqueue(src, dst, is_video)
+            thumbnailer.enqueue(src, _deferred(output_dirs, src, dst), is_video)
         self.logger.info(f"{missing:,} previews missing after the scan; queued")
         return "queued"
 

py/api/thumbnail_convert.py

@@ -153,6 +153,7 @@ class ThumbnailConvertMixin:
             job.log_line("Conversion failed · internal error")
             state = "failed"
         job.finish(state)
+        await self._release_job_memory()
 
     async def _convert_job_body(self, job, options):
         output_dirs = await self._run_in_executor(self._get_all_output_dirs)

py/api/thumbnail_encode.py

@@ -46,7 +46,7 @@ from pathlib import Path
 
 from PIL import Image
 
-from . import thumbnail_settings
+from . import preview_store, thumbnail_settings
 
 try:
     from ...utils.logging_config import get_logger
@@ -101,10 +101,15 @@ def temp_sibling(dst, tag="part"):
 
 
 def replace_unless_held(tmp, dst, guard=None):
-    """Rename *tmp* over *dst*, unless ``guard()`` is false (PreviewWriteHeld)."""
-    if guard is not None and not guard():
-        raise PreviewWriteHeld(PREVIEW_HELD)
-    os.replace(tmp, dst)
+    """Rename *tmp* over *dst*, unless ``guard()`` is false (PreviewWriteHeld).
+
+    The check and the rename run under ``preview_store.write_lock`` (#320): a
+    guard from ``preview_store.write_guard`` also refuses a write that started
+    before the thumbnail location changed."""
+    with preview_store.committed(guard) as allowed:
+        if not allowed:
+            raise PreviewWriteHeld(PREVIEW_HELD)
+        os.replace(tmp, dst)
 
 
 # ``temp_sibling``'s names: ``.<stem>.<tag>-<pid>-<thread id><ext>``.
@@ -158,6 +163,7 @@ def _unlink_quietly(path):
     try:
         Path(path).unlink()
     except FileNotFoundError:
+        # already gone, which is what was wanted
         pass
     except OSError as exc:
         logger.debug(f"Could not remove temp file {Path(path).name}: {exc}")
@@ -221,6 +227,7 @@ def shutdown_encoders():
         try:
             process.kill()
         except OSError:
+            # the process has already exited
             pass
 
 
@@ -359,10 +366,12 @@ def thumbnail_frame(img, edge):
     try:
         img.seek(0)
     except (EOFError, AttributeError, ValueError):
+        # not seekable or a single frame: use the current one
         pass
     try:
         img.draft("RGB", (edge, edge))  # JPEG: decode at a reduced scale
     except (AttributeError, ValueError, OSError):
+        # draft is only a speedup; the full decode below still works
         pass
     frame = img.convert("RGB") if img.mode != "RGB" else img.copy()
     frame.thumbnail((edge, edge), Image.Resampling.LANCZOS)

py/api/thumbnail_jobs.py

@@ -49,6 +49,7 @@ from .images import (
     _worker_threads,
 )
 from .job_routes import busy_response
+from .thumbnail_location import location_refusal
 from .jobs import THUMBNAIL_GROUP_NAMES, THUMBNAILS_JOB_KIND, JobBusy
 from .thumbnail_convert import CONVERT_JOB_TITLE
 from .thumbnail_encode import writer_settings
@@ -182,6 +183,9 @@ class ThumbnailJobsMixin:
         options, error = thumbnail_options(body)
         if error:
             return _invalid(error)
+        refused = location_refusal()
+        if refused is not None:
+            return refused
         try:
             job = self._start_thumbnail_job(options)
         except JobBusy as busy:
@@ -226,6 +230,7 @@ class ThumbnailJobsMixin:
             )
             state = "failed"
         job.finish(state)
+        await self._release_job_memory()
 
     async def _thumbnail_job_body(self, job, options):
         """Plan, then generate in worker batches; returns the final state.
@@ -458,8 +463,12 @@ class ThumbnailJobsMixin:
         or attaches to the running thumbnail job, and streams its frames. A
         legacy hold (the blocking generate or clear) or a record-changing
         job refuses it with the stream's error frame. The job goes on when
-        the client goes away.
+        the client goes away. Refused (409) while the thumbnail folder is
+        unavailable (#320).
         """
+        refused = location_refusal()
+        if refused is not None:
+            return refused
         response = web.StreamResponse(
             status=200,
             headers={

py/api/thumbnail_location.py

@@ -0,0 +1,160 @@
+"""The thumbnail location on the API (#320): startup, the settings payload
+and the refusals while the thumbnail folder is unavailable.
+
+The setting itself is config.json ``thumbnails.location``
+(``preview_location``); the runtime state is ``preview_store``. POST
+``/settings`` never changes it (409 ``location-needs-move``): the Move
+thumbnails job is its only writer.
+"""
+
+import os
+
+from aiohttp import web
+
+from . import preview_location, preview_store
+
+try:
+    from ...utils import library_location
+except ImportError:  # tests import the package top-level
+    from utils import library_location
+
+# The node folder (its web/ is served and a reinstall wipes it).
+NODE_FOLDER = os.path.dirname(
+    os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+)
+
+
+def default_path():
+    """``<data folder>/data/thumbnails`` (D7B), or None when unknown."""
+    try:
+        return library_location.cache_dir("thumbnails")
+    except Exception:  # no data folder can be decided: no default
+        return None
+
+
+def location_refusal(location=None):
+    """The 409 ``location-unavailable`` response while the thumbnail folder
+    is unavailable, else None (thumbnail generate, convert, clear, prune)."""
+    location = location or preview_store.current()
+    if location.mode != preview_store.FOLDER_MODE or location.available:
+        return None
+    status, text = preview_location.message("location-unavailable")
+    return web.json_response(
+        {"success": False, "code": "location-unavailable", "error": text},
+        status=status,
+    )
+
+
+def needs_move_response():
+    status, text = preview_location.message("location-needs-move")
+    return web.json_response(
+        {"success": False, "code": "location-needs-move", "error": text},
+        status=status,
+    )
+
+
+class ThumbnailLocationMixin:
+    """Startup check and payloads of the thumbnail location."""
+
+    def _all_source_roots(self):
+        """Every image source of every root list: the Images roots, the
+        configured sources and the extra gallery roots (as strings)."""
+        from ..config import GalleryConfig, _extra_gallery_roots
+
+        roots = [str(root) for root in self._get_all_output_dirs()]
+        roots += [str(root) for root in GalleryConfig.MONITORING_DIRECTORIES]
+        roots += list(_extra_gallery_roots())
+        return tuple(dict.fromkeys(root for root in roots if root))
+
+    def _thumbnail_location_context(self):
+        """What a thumbnail folder is validated against (blocking)."""
+        contained = []
+        try:
+            import folder_paths
+
+            for name in (
+                "get_output_directory",
+                "get_input_directory",
+                "get_temp_directory",
+            ):
+                getter = getattr(folder_paths, name, None)
+                folder = getter() if getter is not None else None
+                if folder:
+                    contained.append(str(folder))
+        except ImportError:
+            pass
+        try:
+            contained.append(library_location.config_location()[1])
+        except Exception:  # no data folder can be decided
+            self.logger.debug("No library folder for the thumbnail check")
+        setting = preview_store.setting()
+        return preview_location.Context(
+            roots=self._all_source_roots(),
+            contained=tuple(contained),
+            node_folder=NODE_FOLDER,
+            default_path=default_path(),
+            current_path=(
+                setting.path if setting.mode == preview_store.FOLDER_MODE else None
+            ),
+        )
+
+    def use_preview_location(self):
+        """Put the configured location in force at once, unchecked (the
+        package's import, before any request): folder mode is unavailable
+        until ``start_preview_location`` has checked it, so nothing is ever
+        written to the sources meanwhile. No filesystem access."""
+        from ..config import PromptManagerConfig
+
+        try:
+            return preview_store.configure(
+                PromptManagerConfig.THUMBNAIL_LOCATION, check=False
+            )
+        except Exception:
+            self.logger.warning("The thumbnail location is unusable", exc_info=True)
+            preview_store.mark_invalid()
+            return preview_store.current()
+
+    def start_preview_location(self):
+        """Parse and check the configured location once (startup thread);
+        the probe takes over. Never raises; a check that fails leaves a
+        folder location unavailable (``invalid``), never the sources."""
+        from ..config import PromptManagerConfig
+
+        try:
+            value = PromptManagerConfig.THUMBNAIL_LOCATION
+            parsed = preview_location.parse_location(value)
+            context = None
+            if parsed.mode == preview_store.FOLDER_MODE:
+                context = self._thumbnail_location_context()
+            location = preview_store.configure(value, context=context)
+        except Exception:
+            self.logger.warning("The thumbnail location check failed", exc_info=True)
+            if (
+                preview_location.parse_location(
+                    PromptManagerConfig.THUMBNAIL_LOCATION
+                ).mode
+                == preview_store.FOLDER_MODE
+            ):
+                preview_store.mark_invalid()
+            return preview_store.current()
+        if location.mode == preview_store.FOLDER_MODE and not location.available:
+            self.logger.warning(
+                "The thumbnail folder is unavailable "
+                f"({location.problem or 'checking'}): originals are shown and "
+                "no thumbnails are written until it is back"
+            )
+        return location
+
+    def _thumbnail_location_payload(self, *, with_path):
+        """``{mode, available, problem}`` plus, for the settings GET only,
+        ``path`` and ``default_path`` (D6A)."""
+        location = preview_store.current()
+        payload = {
+            "mode": location.mode,
+            "available": location.available,
+            "problem": location.problem,
+        }
+        if with_path:
+            payload["path"] = location.path
+            payload["default_path"] = default_path()
+        return payload

py/api/thumbnail_settings.py

@@ -114,9 +114,16 @@ def validate_edge(value):
 # ── names ────────────────────────────────────────────────────────────
 
 
+def preview_stem(rel_path):
+    """``<rel without extension>_thumb`` (POSIX): a preview's name inside the
+    store of its source (``preview_store``)."""
+    return f"{Path(rel_path).with_suffix('').as_posix()}{THUMB_SUFFIX}"
+
+
 def thumbnail_stem_rel(rel_path):
-    """``thumbnails/<rel without extension>_thumb`` (POSIX)."""
-    return f"thumbnails/{Path(rel_path).with_suffix('').as_posix()}{THUMB_SUFFIX}"
+    """``thumbnails/<rel without extension>_thumb`` (POSIX): URL text only.
+    Where the preview is on disk is ``preview_store``'s answer."""
+    return f"thumbnails/{preview_stem(rel_path)}"
 
 
 def thumbnail_rel(rel_path, extension=None):
@@ -207,9 +214,20 @@ def owned_in_folder(folder, stem, source_extension, preferred=None):
 
 
 def _owned(root, rel_path, preferred):
+    from . import preview_store
+
     rel_path = Path(rel_path)
-    stem = Path(root) / thumbnail_stem_rel(rel_path)
-    return owned_in_folder(stem.parent, stem.name, rel_path.suffix, preferred)
+    store = preview_store.store_dir(root)
+    if store is None:
+        return iter(())
+    stem = store / preview_stem(rel_path)
+    found = owned_in_folder(stem.parent, stem.name, rel_path.suffix, preferred)
+    if preview_store.current().mode == preview_store.SOURCE_MODE:
+        return found
+    # Folder mode: timed, so a stalled share marks the folder unreachable,
+    # and only previews no link takes out of the key folder (deletes use it).
+    with preview_store.store_io():
+        return iter([path for path in found if preview_store.may_write(path)])
 
 
 def owned_thumbnails(root, rel_path, preferred=None):

py/api/workflow_storage.py

@@ -275,3 +275,4 @@ class WorkflowStorageRoutesMixin:
         job.record_counted("changed", 1)
         job.log_line(line)
         job.update(progress=100, status_line=line)
+        return None

py/config.py

@@ -767,6 +767,8 @@ class PromptManagerConfig:
     THUMBNAIL_QUALITY = 80
     THUMBNAIL_EDGE = 512
     THUMBNAIL_EDGE_RANGE = (128, 2048)
+    # #320 thumbnail location (config.json ``thumbnails.location``), as read.
+    THUMBNAIL_LOCATION = None
 
     @classmethod
     def max_worker_threads(cls) -> int:
@@ -828,6 +830,12 @@ class PromptManagerConfig:
                 "format": cls.THUMBNAIL_FORMAT,
                 "quality": cls.THUMBNAIL_QUALITY,
                 "edge": cls.THUMBNAIL_EDGE,
+                # #320: as read; only the Move thumbnails job writes it.
+                **(
+                    {"location": cls.THUMBNAIL_LOCATION}
+                    if cls.THUMBNAIL_LOCATION is not None
+                    else {}
+                ),
             },
             "gallery": GalleryConfig.get_config(),
             "integrations": IntegrationConfig.get_config(),
@@ -1002,6 +1010,11 @@ class PromptManagerConfig:
         low, high = cls.THUMBNAIL_EDGE_RANGE
         if type(edge) is int and low <= edge <= high:
             cls.THUMBNAIL_EDGE = edge
+        # #320: kept as read (``preview_location.parse_location`` checks it;
+        # a bad value becomes an unavailable ``invalid`` location, never a
+        # silent fall-back to the sources).
+        if "location" in section:
+            cls.THUMBNAIL_LOCATION = section["location"]
 
 
 # Load configuration on import

py/config_store.py

@@ -109,6 +109,7 @@ def _write_atomically(path: str, payload: bytes) -> None:
         try:
             os.unlink(temp_path)
         except OSError:
+            # nothing to clean up; the original error is raised below
             pass
         raise
 

py/lora_manager_layout.py

@@ -642,6 +642,7 @@ def layout_summary(layout: LoraManagerLayout, home: Path) -> Dict:
             relative = Path(settings_file).relative_to(home)
             settings_file = os.path.join("~", str(relative))
         except ValueError:
+            # outside the home folder: show the full path
             pass
     return {
         "source": layout.source,

py/lora_utils.py

@@ -585,6 +585,7 @@ def _read_capped(resp, cap: int) -> Optional[bytes]:
             if int(declared) > cap:
                 return None
         except ValueError:
+            # a bad header says nothing; the read below enforces the cap
             pass
 
     chunks = []
@@ -707,6 +708,7 @@ def _save_atomically(image, local_path: Path) -> None:
         try:
             os.remove(temp)
         except OSError:
+            # nothing to clean up; the original error is raised below
             pass
         raise
 

pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "promptmanager"
 description = "A powerful ComfyUI custom node that extends the standard text encoder with persistent prompt storage, advanced search capabilities, and an automatic image gallery system using SQLite."
-version = "3.4.0"
+version = "3.4.1"
 license = {file = "LICENSE"}
 requires-python = ">=3.12"
 dependencies = ["watchdog>=2.1.0", "Pillow>=8.0.0"]

requirements.txt

@@ -1,4 +1,4 @@
 # Runtime dependencies for PromptManager.
 # aiohttp, numpy and torch come from ComfyUI itself and are not listed here.
-watchdog>=2.1.0              # Output directory monitoring
+watchdog>=2.1.0               # Output directory monitoring
 Pillow>=8.0.0                # Image metadata extraction and thumbnails

tests/browser/activity-concept.spec.mjs

@@ -6,7 +6,6 @@ import { THEMES, seedConcept, openConcept, openProduction, diffInventory, mutate
 // app.js 1428–1432) and its backup box with the concept's System `.notice`; the differences are D55. The job view
 // has no concept counterpart: it is compared with the approved mockup `activity-scan.html` (a local, ignored file),
 // whose structure and CSS values are restated below (D56). Each comparison is shown to notice a mutation.
-const workspace = '/prompt_manager/workspace';
 
 test.beforeEach(async ({ page, request, browserName }) => {
     await startCoverage(page, browserName);

tests/browser/prompt-inspector.spec.mjs

@@ -320,3 +320,44 @@ test('copy toast and fallback dialog',async({page})=>{
     await expect(fallback).toContainText('Automatic clipboard access requires a secure browser context.');
     await page.keyboard.press('Escape');await expect(fallback).toBeHidden();await expect(copy).toBeFocused();
 });
+
+// #542 D191: "All N eligible nodes" previews every node, sends one after another and names each refusal.
+test('All eligible nodes previews each node, sends in node id order and names a refusal',async({page,context},testInfo)=>{
+    const host=await context.newPage();await host.goto('/prompt_manager/workspace#/overview');
+    await host.evaluate(async()=>{
+        const {createBridgeHost}=await import('/prompt_manager/js/shared/toolkit/prompt-bridge.js');
+        const targets=['12','3','7'].map(id=>({id,label:id==='7'?'Edited in ComfyUI':'Prompt Manager (+/-)',type:'PromptManagerPair',roles:['positive','negative']}));
+        window.hostValues=Object.fromEntries(targets.map(target=>[target.id,{positive:`Existing ${target.id}`,negative:'Existing negative'}]));window.applied=[];
+        window.fixtureHost=createBridgeHost({origin:location.origin,namespace:'/',label:'Test ComfyUI',adapter:{
+            listTargets:()=>targets,
+            preview:(id,roles)=>{const target=targets.find(item=>item.id===id);return{preview:{target,fields:Object.entries(roles).map(([role,after])=>({role,before:window.hostValues[id][role],after}))},snapshot:{id,roles}};},
+            apply:({id,roles})=>{if(id==='7')throw new Error('Workflow or prompt changed. Preview again.');Object.assign(window.hostValues[id],roles);window.applied.push(id);return{targetId:id,values:roles};},
+        }});
+    });
+    try {
+        await page.goto(workspace);await select(page,'0:shared/same.png');await details(page).getByRole('button',{name:/^Send prompt pair to ComfyUI: /}).click();
+        const sender=dialog(page);const nodes=sender.getByRole('combobox',{name:'Destination node',exact:true});
+        await sender.getByRole('combobox',{name:'ComfyUI window',exact:true}).selectOption({label:'Test ComfyUI'});
+        await expect(nodes.locator('option')).toHaveText(['Choose a destination node','#12 Prompt Manager (+/-)','#3 Prompt Manager (+/-)','#7 Edited in ComfyUI','All 3 eligible nodes']);
+        await expect(nodes).toHaveValue('');
+        await nodes.selectOption({label:'All 3 eligible nodes'});
+        await expect(sender.getByRole('status')).toHaveText('Sending to all 3 eligible nodes in Test ComfyUI. Apply to send it, or preview the changes first.');
+        await page.screenshot({path:testInfo.outputPath('send-all-option.png')});
+        await sender.getByRole('button',{name:'Preview changes',exact:true}).click();
+        const reviews=sender.locator('section.prompt-sender-node');
+        await expect(reviews.locator('> h4')).toHaveText(['#3 Prompt Manager (+/-)','#7 Edited in ComfyUI','#12 Prompt Manager (+/-)']);
+        await expect(sender.getByRole('region',{name:'#12 Prompt Manager (+/-)',exact:true})).toContainText('Existing 12');
+        expect(await host.evaluate(()=>window.applied)).toEqual([]);
+        await sender.getByRole('button',{name:'Apply to ComfyUI',exact:true}).click();
+        await expect(sender.getByRole('alert')).toHaveText('Sent to 2 of 3 nodes in Test ComfyUI. #7 Edited in ComfyUI: Workflow or prompt changed. Preview again.');
+        expect(await host.evaluate(()=>window.applied)).toEqual(['3','12']);
+        expect(await host.evaluate(()=>window.hostValues['7'].positive)).toBe('Existing 7');
+        await page.screenshot({path:testInfo.outputPath('send-all-result.png')});
+        await page.setViewportSize({width:390,height:844});
+        await sender.getByRole('button',{name:'Preview changes',exact:true}).click();await expect(reviews).toHaveCount(3);
+        await reviews.last().scrollIntoViewIfNeeded();
+        expect(await page.evaluate(()=>document.querySelector('dialog.prompt-sender').scrollWidth<=document.querySelector('dialog.prompt-sender').clientWidth+1)).toBe(true);
+        await page.screenshot({path:testInfo.outputPath('send-all-mobile.png')});
+        const apply=sender.getByRole('button',{name:'Apply to ComfyUI',exact:true});await apply.focus();await expect(apply).toBeFocused();
+    } finally {await host.evaluate(()=>window.fixtureHost.dispose());await host.close();}
+});

tests/browser/server.py

@@ -22,6 +22,9 @@ from PIL.PngImagePlugin import PngInfo
 from tests.browser.folder_trash import close_trash, replace_folder
 from tests.browser.malloc_tuning import pin_mmap_threshold
 from tests.browser.request_hold import register_request_holds
+from tests.browser.thumbnail_location_fixture import (
+    register_thumbnail_location_commands,
+)
 from tests.browser import slow_reset_watch
 from tests.browser.fast_reset import SEED_ON_LIVE_ENV, ScratchSeeder
 from tests.browser.workspace_activity_fixture import register_activity_commands
@@ -240,6 +243,7 @@ def create_app(root: Path) -> web.Application:
     library_editor_commands = register_library_editor_commands(routes, api, root)
     register_vocabulary_commands(routes, api, root)
     restore_sources = register_source_change_commands(routes, api)
+    reset_thumbnail_location = register_thumbnail_location_commands(routes, api, root)
     register_tagging_commands(routes, api, root, model, on_reset=restore_sources)
     register_review_commands(routes, api, root)
     register_collections_commands(routes, api, root)
@@ -451,6 +455,8 @@ def create_app(root: Path) -> web.Application:
         restore_sources()
         # No preview queued by the last test may land in the new fixture.
         await api._run_in_executor(api.close_auto_thumbnails)
+        # Previews inside each source again (#320).
+        await api._run_in_executor(reset_thumbnail_location)
         library_editor_commands.reset()
         await api._run_in_executor(reset_logs)
         data = await request.json() if request.can_read_body else {}
@@ -595,6 +601,7 @@ def create_app(root: Path) -> web.Application:
         history_commands.reset()
         library_editor_commands.reset()
         reveal_stub.reset()
+        await api._run_in_executor(reset_thumbnail_location)
         history_fixture = None
         manifest = await api._run_in_executor(
             seeder.run,

tests/browser/slow_reset_watch.py

@@ -109,6 +109,7 @@ class ResetWatch:
             stream.write(text)
             stream.flush()
         except (OSError, ValueError):
+            # the stream closed; a watcher must not fail the server
             pass
 
 

tests/browser/system-concept.spec.mjs

@@ -162,13 +162,15 @@ async function serverJson(request, url) {
 }
 
 const number = value => value.toLocaleString('en-US');
+// The sidebar's Images count (state.mjs), which System's Images metric shows (#555).
+const IMAGES_COUNT_URL = '/prompt_manager/images/output?mode=workspace&limit=1';
 
 /** The concept's shell and Overview with the recorded deviations applied, given the server's real overview. */
-function mapOverviewConcept(reference, overview) {
+function mapOverviewConcept(reference, overview, images) {
     // D165: the discreet legacy-pages line follows the settings layout.
     reference = { ...reference, tree: [...reference.tree, 'p.legacy-pages.small'] };
     const relabel = { 'Database integrity': 'Not checked', 'Positive prompts': number(overview.library.positive_prompts),
-        'Negative variants': number(overview.library.negative_variants), Images: number(overview.images.indexed) };
+        'Negative variants': number(overview.library.negative_variants), Images: number(images) };
     const rows = {
         // D93: the real pending count; Review metadata opens Needs review (the concept's go-review).
         '3 ambiguous image links': row => ({ ...row,
@@ -179,8 +181,9 @@ function mapOverviewConcept(reference, overview) {
         'One display configuration': row => ({ ...row, description: 'Grid and density settings are shared across views.' }),
         // D93: the real sources, not samples.
         '2 sample output sources': row => ({ ...row, title: `${number(overview.sources.effective)} output sources` }),
-        // D96: the dialog shows runs by category and library totals, not prompt, tag or date usage (D153: no ratings).
-        Statistics: row => ({ ...row, description: 'Runs by category, with library totals.' }),
+        // D96: the dialog shows runs by category and database record counts, not prompt, tag or date usage (D153: no
+        // ratings; #555: the counts are labelled as records, not as the Library or Images page counts).
+        Statistics: row => ({ ...row, description: 'Runs by category, with database record counts.' }),
     };
     const surfaces = reference.columns.surfaces.map(surface => ({ ...surface,
         rows: surface.rows.map(row => (rows[row.title] ?? (value => value))(row)) }));
@@ -218,6 +221,8 @@ async function conceptOverview(page, theme) {
 async function productionOverview(page, theme) {
     await openProduction(page, 'system/overview', theme);
     await expect(page.locator('#workspace-main .summary-metrics')).toBeVisible();
+    // #555: the Images metric is the shell's Images count: compare once it was read.
+    await expect(page.locator('#workspace-main .summary-metrics > .metric:nth-child(3) strong')).toHaveText(/^[\d,]+$/);
     // The thumbnail row is its own read (I2): compare once it answered.
     await expect(page.locator('#workspace-main .operation h3').filter({ hasText: 'thumbnails' })).toHaveText('No missing thumbnails');
     // So is the backup row (S9).
@@ -231,6 +236,7 @@ for (const theme of THEMES) for (const [width, height] of SIZES) {
     test(`system shell and overview match the concept ${theme} ${width}x${height}`, async ({ page, request }, testInfo) => {
         await page.setViewportSize({ width, height });
         const overview = await serverJson(request, '/prompt_manager/system/overview');
+        const images = (await serverJson(request, IMAGES_COUNT_URL)).total;
         // The fixture's thumbnails all exist, so the concept's "No missing thumbnails" is also the real title.
         expect((await serverJson(request, '/prompt_manager/images/thumbnails/status')).pending).toBe(0);
         const concept = await conceptOverview(page, theme);
@@ -239,7 +245,7 @@ for (const theme of THEMES) for (const [width, height] of SIZES) {
         await page.screenshot({ path: testInfo.outputPath(`concept-system-${theme}-${width}.png`), fullPage: true });
         const production = await productionOverview(page, theme);
         await page.screenshot({ path: testInfo.outputPath(`production-system-${theme}-${width}.png`), fullPage: true });
-        expect(diffInventory(mapOverviewConcept(concept, overview), production)).toEqual([]);
+        expect(diffInventory(mapOverviewConcept(concept, overview, images), production)).toEqual([]);
         expect(production.pageScroll).toBe(false);
     });
 }
@@ -265,8 +271,9 @@ const UNMAPPED_PATHS = [
 test('system comparison detects mutations', async ({ page, request }) => {
     await page.setViewportSize({ width: 1600, height: 1100 });
     const overview = await serverJson(request, '/prompt_manager/system/overview');
+    const images = (await serverJson(request, IMAGES_COUNT_URL)).total;
     const concept = await conceptOverview(page, 'dark');
-    const expected = mapOverviewConcept(concept, overview);
+    const expected = mapOverviewConcept(concept, overview, images);
     const production = await productionOverview(page, 'dark');
     expect(diffInventory(expected, production)).toEqual([]);
     // Unmapped, the concept differs exactly where a deviation is recorded, and nowhere else.
@@ -290,7 +297,7 @@ test('system comparison detects mutations', async ({ page, request }) => {
 });
 
 /**
- * D96: the concept's table, its rows the real ones; then "Library totals" in the same table markup. D153 (#447): the
+ * D96: the concept's table, its rows the real ones; then "Database records" (#555) in the same table markup. D153 (#447): the
  * concept's "Avg. rating" column and a "Rated images" total are not drawn.
  */
 function mapStatisticsConcept(reference, statistics) {
@@ -302,9 +309,10 @@ function mapStatisticsConcept(reference, statistics) {
         tables: [
             { ...runs, head: runs.head.filter(([, , text]) => text !== 'Avg. rating'),
                 rows: statistics.by_category.map(row => [row.category ?? 'Uncategorized', number(row.runs)]) },
-            { caption: 'Library totals', head: [['th', 'col', 'Total'], ['th', 'col', 'Count']],
-                rows: [['Prompts', number(statistics.totals.total_prompts)], ['Tags', number(statistics.totals.total_tags)],
-                    ['Images', number(statistics.totals.total_images)]] },
+            { caption: 'Database records', head: [['th', 'col', 'Total'], ['th', 'col', 'Count']],
+                rows: [['Prompt records', number(statistics.totals.total_prompts)],
+                    ['Tags on prompts', number(statistics.totals.total_tags)],
+                    ['Image records', number(statistics.totals.total_images)]] },
         ],
     };
 }
@@ -420,7 +428,7 @@ for (const theme of THEMES) test(`statistics and health dialogs match the concep
     expect(diffInventory(mapHealthConcept(concept.health), await page.evaluate(measureDialog)).map(item => item.path))
         .toEqual(['operations.rows.0.title']);
     await page.evaluate(() => { document.querySelector('#modal .operation h3').textContent = 'Integrity check'; });
-    // And a removed "Library totals" table and a changed caption in the statistics dialog.
+    // And a removed "Database records" table and a changed caption in the statistics dialog.
     await page.keyboard.press('Escape');
     await page.locator('#workspace-main .section-nav').getByRole('button', { name: 'Overview', exact: true }).click();
     await page.locator('#workspace-main').getByRole('button', { name: 'Explore', exact: true }).click();

tests/browser/thumbnail_location_fixture.py

@@ -0,0 +1,92 @@
+"""The thumbnail location on the test server (#320), undone by every reset.
+
+Folder mode is reachable from config.json and tests only until the Move
+thumbnails job lands, so page tests set it here, inside the server's root:
+
+- ``POST /__test__/thumbnail-location`` ``{"mode": "folder"}`` (or
+  ``"source"``): previews live in ``<root>/thumbs/<key>`` from now on (a new
+  folder with Prompt Manager's marker).
+- ``GET /__test__/thumbnail-files``: the preview files in the thumbnail
+  folder and whether any source grew a ``thumbnails/`` folder.
+- ``POST /__test__/thumbnail-folder/remove``: the thumbnail folder goes, as
+  when its drive is unplugged; the server notices it on its next check.
+"""
+
+from __future__ import annotations
+
+import shutil
+from pathlib import Path
+from typing import TYPE_CHECKING, Callable
+
+from aiohttp import web
+
+if TYPE_CHECKING:
+    from py.api import PromptManagerAPI
+
+FOLDER_NAME = "thumbs"
+
+
+def register_thumbnail_location_commands(
+    routes: web.RouteTableDef, api: PromptManagerAPI, root: Path
+) -> Callable[[], None]:
+    """Register the commands; returns the reset every reset runs."""
+    from py.api import preview_location, preview_store
+
+    folder = root / FOLDER_NAME
+
+    def reset() -> None:
+        preview_store.configure(None)
+        shutil.rmtree(folder, ignore_errors=True)
+
+    def use(mode: str) -> dict:
+        reset()
+        if mode == "source":
+            return {"mode": "source"}
+        folder.mkdir()
+        marker_id = preview_location.init_folder(str(folder), created_by_pm=True)
+        location = preview_store.configure(
+            {
+                "mode": "folder",
+                "path": str(folder),
+                "id": marker_id,
+                "install": "browser-tests",
+            }
+        )
+        return {"mode": location.mode, "available": location.available}
+
+    @routes.post("/__test__/thumbnail-location")
+    async def set_location(request: web.Request) -> web.Response:
+        data = await request.json()
+        mode = data.get("mode") if isinstance(data, dict) else None
+        if mode not in ("source", "folder"):
+            raise web.HTTPBadRequest()
+        return web.json_response(await api._run_in_executor(use, mode))
+
+    def files() -> dict:
+        previews = sorted(
+            path.relative_to(folder).as_posix()
+            for path in folder.rglob("*_thumb.*")
+            if path.is_file()
+        )
+        sources = [str(path) for path in api._get_all_output_dirs()]
+        return {
+            "folder": previews,
+            "source_thumbnails": any(
+                (Path(source) / "thumbnails").exists() for source in sources
+            ),
+        }
+
+    @routes.get("/__test__/thumbnail-files")
+    async def thumbnail_files(_request: web.Request) -> web.Response:
+        return web.json_response(await api._run_in_executor(files))
+
+    def remove() -> bool:
+        shutil.rmtree(folder, ignore_errors=True)
+        return preview_store.refresh()
+
+    @routes.post("/__test__/thumbnail-folder/remove")
+    async def remove_folder(_request: web.Request) -> web.Response:
+        available = await api._run_in_executor(remove)
+        return web.json_response({"available": available})
+
+    return reset

tests/browser/workflows.spec.mjs

@@ -261,3 +261,20 @@ test('prompt deletion requires confirmation and can retry after a network failur
         await expect(await request.get(url)).toBeOK();
     }
 });
+
+// #320: with previews in one folder, the legacy gallery still shows them, made
+// and served from that folder (the fixture's own previews inside the sources
+// are never served then).
+test('the legacy gallery shows thumbnails kept in one folder', async ({ page, request }) => {
+    await expect(await request.post('/__test__/thumbnail-location', { data: { mode: 'folder' } })).toBeOK();
+    const served = page.waitForResponse(response =>
+        response.url().includes('/prompt_manager/images/serve/thumbnails/') && response.status() === 200);
+    await page.goto('/prompt_manager/gallery');
+    await expect(page.locator('#galleryGrid .image-item')).toHaveCount(2);
+    const response = await served; // made in the folder before it was served
+    const name = decodeURIComponent(new URL(response.url()).pathname.split('/serve/thumbnails/')[1]);
+    const files = await (await request.get('/__test__/thumbnail-files')).json();
+    const stem = name.replace(/\.[^.]+$/, '');
+    expect(files.folder.some(file => /^[a-z0-9_-]+-[0-9a-f]{8}\//.test(file)
+        && file.slice(file.indexOf('/') + 1).replace(/\.[^.]+$/, '') === stem)).toBe(true);
+});

tests/browser/workspace-layout-tags-system.spec.mjs

@@ -156,8 +156,9 @@ test('at 390px the window fits the screen, actions stay reachable and the page s
     expect(frame.bottom-frame.top).toBeLessThan(844);
     expect(frame.bottom-frame.top).toBeGreaterThanOrEqual(280);
     expect(await page.evaluate(()=>document.documentElement.scrollWidth)).toBeLessThanOrEqual(390);
-    // The last row's actions can be scrolled to inside the window and fit its width.
-    const last=rows(page).last().getByRole('button',{name:'Rename / merge',exact:true});
+    // The first page's last row's actions can be scrolled to inside the window and fit its width.
+    // Pinned to row 100: reaching it loads the next page (D183), and last() would then follow row 200.
+    const last=rows(page).nth(99).getByRole('button',{name:'Rename / merge',exact:true});
     await last.scrollIntoViewIfNeeded();await expect(last).toBeInViewport();
     const [button]=await boxes(last);const [after]=await boxes(tagWindow(page));
     expect(button.right).toBeLessThanOrEqual(after.right);

tests/browser/workspace-saved-views.spec.mjs

@@ -233,7 +233,7 @@ test('a view stored under older rules still lists and opens with its usable valu
 // D153 (#447): the workspace no longer offers "Highest rated"; the API still stores such a view as it was saved.
 test('a view saved under Highest rated opens on Recently added on Images and the Library', async ({ page, request }) => {
     const images = await create(request, { page: 'images', name: 'Rated cats', state: { ...IMAGE_DEFAULTS, q: 'cat', sort: 'rating' } });
-    const library = await create(request, { page: 'library', name: 'Rated dogs', state: { q: 'dog', category: '', sort: 'rating', tags: [], tag_mode: 'all', folder: '' } });
+    await create(request, { page: 'library', name: 'Rated dogs', state: { q: 'dog', category: '', sort: 'rating', tags: [], tag_mode: 'all', folder: '' } });
     expect((await listed(request)).map(view => view.state.sort)).toEqual(['rating', 'rating']);
     const listings = [];
     page.on('request', item => {

tests/browser/workspace-sticky-chrome.spec.mjs

@@ -60,7 +60,7 @@ async function openReview(page, request, items = 30) {
 const inViewport = (rect, page) => rect.top >= 0 && rect.bottom <= page.viewportSize().height;
 
 test.beforeEach(async ({ page, browserName }) => { await startCoverage(page, browserName); });
-test.afterEach(async ({ page, browserName }, testInfo) => { await saveCoverage(page, browserName, testInfo); });
+test.afterEach(async ({ page, browserName }) => { await saveCoverage(page, browserName); });
 
 for (const viewport of [null, PHONE]) {
     const label = viewport ? ' at 390px' : '';

tests/browser/workspace-system-backups.spec.mjs

@@ -284,6 +284,23 @@ test('a restore seen finishing elsewhere closes an open restore review and disca
     expect((await serverJson(request, '/__test__/system/backups')).stages).toBe(0);
 });
 
+// #583: in WebKit, while a page.route is armed, a file part of a FormData body is read only when the request goes on;
+// a garbage collection in between dropped the form once nothing referenced it, and the server got an empty file
+// ("Uploaded file is empty"). The page keeps the form until its upload is answered. The route holds the upload
+// through a collection; without the fix WebKit lost the file every time (0/10 in the pinned image). Chromium and
+// Firefox keep the body anyway, so there it only checks that a held upload still opens the review.
+test('a review upload survives a garbage collection while it is in flight', async ({ page, request }) => {
+    const bytes = await backupBytes(request);
+    await page.route(`**${PREVIEW_URL}`, async route => {
+        await page.requestGC();
+        await route.continue();
+    });
+    await openBackups(page);
+    expect((await chooseBackup(page, bytes)).status()).toBe(200);
+    await expect(dialog(page).locator('#modal-title')).toHaveText('Restore preview');
+    expect((await serverJson(request, '/__test__/system/backups')).stages).toBe(1);
+});
+
 test('invalid file shows the validator message; nothing is staged', async ({ page, request }) => {
     const before = await serverJson(request, '/__test__/system/digest');
     await openBackups(page);

tests/browser/workspace-system-diagnostics.spec.mjs

@@ -11,7 +11,6 @@ const REPORT_URL = '/prompt_manager/system/diagnostics';
 const LOGS_URL = '/prompt_manager/logs';
 const CONFIG_URL = '/prompt_manager/logs/config';
 const PREVIEW_URL = '/prompt_manager/maintenance/preview';
-const APPLY_URL = '/prompt_manager/maintenance/apply';
 const TEST_LINK_URL = '/prompt_manager/diagnostics/test-link';
 const CHANGED = 'The log files changed since the review; nothing was deleted. Review again.';
 const KEY = 'sk-s12-browser-SECRET-0123456789';

tests/browser/workspace-system.spec.mjs

@@ -8,6 +8,8 @@ import { readCoverageTable, parseControl, CONTROL_EXEMPTIONS } from '../../tools
 const workspace = '/prompt_manager/workspace';
 const OVERVIEW_URL = '/prompt_manager/system/overview';
 const THUMBNAILS_URL = '/prompt_manager/images/thumbnails/status';
+// The sidebar's Images count (state.mjs NAV_COUNT_SOURCES): the Images page's own total.
+const IMAGES_COUNT_URL = '/prompt_manager/images/output?mode=workspace&limit=1';
 const number = value => value.toLocaleString('en-US');
 
 test.beforeEach(async ({ page, request, browserName }) => {
@@ -55,6 +57,7 @@ test('overview shows real counts and Not checked', async ({ page, request }) =>
     page.on('request', item => { if (!['GET', 'HEAD', 'OPTIONS'].includes(item.method())) writes.push(item.url()); });
     const overview = await serverJson(request, OVERVIEW_URL);
     const thumbnails = await serverJson(request, THUMBNAILS_URL);
+    const images = (await serverJson(request, IMAGES_COUNT_URL)).total;
     // The concept fixture: six positives, their saved negatives and 24 linked images, all with thumbnails.
     expect([overview.library.positive_prompts, overview.images.indexed, thumbnails.pending]).toEqual([6, 24, 0]);
     // I2: the Overview never walks the sources for thumbnails; the row reads the status route itself.
@@ -66,7 +69,8 @@ test('overview shows real counts and Not checked', async ({ page, request }) =>
         [item.querySelector('strong').textContent, item.querySelector('span').textContent]))).toEqual([
         [number(overview.library.positive_prompts), 'Positive prompts'],
         [number(overview.library.negative_variants), 'Negative variants'],
-        [number(overview.images.indexed), 'Images'],
+        // #555: the Images page's own count, the same number as its sidebar badge.
+        [number(images), 'Images'],
         ['Not checked', 'Database integrity'],
     ]);
     expect(await rowsOf(layout, 'Library health')).toEqual([
@@ -79,11 +83,31 @@ test('overview shows real counts and Not checked', async ({ page, request }) =>
     expect(await rowsOf(layout, 'Workspace preferences')).toEqual([
         ['One display configuration', 'Grid and density settings are shared across views.', 'Appearance'],
         ['2 output sources', 'Monitoring and enrichment share one source list.', 'Manage sources'],
-        ['Statistics', 'Runs by category, with library totals.', 'Explore'],
+        ['Statistics', 'Runs by category, with database record counts.', 'Explore'],
     ]);
     expect(writes).toEqual([]);
 });
 
+test('#555: the Images metric is the sidebar Images count, not the indexed image rows', async ({ page, request }) => {
+    const overview = await serverJson(request, OVERVIEW_URL);
+    // The Images page lists files no row links (the demo library: 122 files, 110 rows); the listing says so.
+    const listed = overview.images.indexed + 12;
+    await page.route(`**${IMAGES_COUNT_URL}`, async route => {
+        const response = await route.fetch();
+        await route.fulfill({ response, json: { ...(await response.json()), total: listed } });
+    });
+    const layout = await openOverview(page);
+    const imagesMetric = layout.locator('.summary-metrics > .metric').filter({ has: page.locator('span', { hasText: /^Images$/ }) });
+    await expect(imagesMetric.locator('strong')).toHaveText(number(listed));
+    await expect(page.locator('#primary-nav a[data-route="images"] .nav-count')).toHaveText(number(listed));
+    // A failed count reads as a dash, never the row count.
+    await page.unroute(`**${IMAGES_COUNT_URL}`);
+    await page.route(`**${IMAGES_COUNT_URL}`, route => route.fulfill({ status: 503, json: { success: false, error: 'Unavailable' } }));
+    await page.goto(`${workspace}#/system/appearance`);
+    await page.locator('#workspace-main .section-nav').getByRole('button', { name: 'Overview', exact: true }).click();
+    await expect(imagesMetric.locator('strong')).toHaveText('–');
+});
+
 // D129 (#249 S6b): where the library lives. The hook makes the fixture's database read as a node-folder library; its
 // Move library is a stand-in that touches no file (workspace_system_fixture.py).
 const banner = page => page.locator('#library-banner');
@@ -364,7 +388,7 @@ test('View backups / Appearance / Manage sources switch sections', async ({ page
     }
 });
 
-test('statistics dialog lists runs by category and library totals', async ({ page, request }) => {
+test('statistics dialog lists runs by category and database record counts', async ({ page, request }) => {
     const statistics = await serverJson(request, '/prompt_manager/system/statistics');
     expect(statistics.by_category.length).toBeGreaterThan(1);
     const layout = await openOverview(page);
@@ -373,13 +397,14 @@ test('statistics dialog lists runs by category and library totals', async ({ pag
     const dialog = page.locator('dialog#modal[open]');
     await expect(dialog.locator('#modal-title')).toHaveText('Usage statistics');
     const tables = dialog.locator('#modal-body > table');
-    await expect(tables.locator('caption')).toHaveText(['Runs by category', 'Library totals']);
+    await expect(tables.locator('caption')).toHaveText(['Runs by category', 'Database records']);
     // D153 (#447): no rating column and no rated-images total.
     await expect(tables.first().locator('thead th')).toHaveText(['Category', 'Runs']);
     const cells = table => table.locator('tbody tr').evaluateAll(rows => rows.map(row => [...row.cells].map(cell => cell.textContent)));
     expect(await cells(tables.first())).toEqual(statistics.by_category.map(row => [row.category ?? 'Uncategorized', number(row.runs)]));
-    expect(await cells(tables.nth(1))).toEqual([['Prompts', number(statistics.totals.total_prompts)],
-        ['Tags', number(statistics.totals.total_tags)], ['Images', number(statistics.totals.total_images)]]);
+    // #555: raw rows of the legacy /stats, labelled as rows so they never read as the Library or Images page counts.
+    expect(await cells(tables.nth(1))).toEqual([['Prompt records', number(statistics.totals.total_prompts)],
+        ['Tags on prompts', number(statistics.totals.total_tags)], ['Image records', number(statistics.totals.total_images)]]);
     await page.keyboard.press('Escape');
     await expect(explore).toBeFocused();
     // A statistics read that fails says so; the Overview stays.

tests/browser/workspace-vocabulary.spec.mjs

@@ -145,9 +145,10 @@ test('long vocabularies append and Load more is keyboard reachable',async({page,
     await expect(loadMore(page)).toHaveCount(0);
     await expect(rows(page).nth(200).getByRole('button',{name:'Browse',exact:true})).toBeFocused();
     await expect(rows(page).locator('td:nth-child(1)')).toHaveText(manifest.tags);
-    // Reload with the window at its top: Firefox restores a scrolled window, whose end then appends a page before the check.
-    await main(page).locator('.two-col .table-wrap').evaluate(node=>new Promise(resolve=>{node.scrollTop=0;requestAnimationFrame(()=>requestAnimationFrame(resolve));}));
-    await page.reload();
+    // Open the screen as a new history entry, not a reload: Firefox restores a reloaded page's scrolled tag window, and
+    // its end then appends a page before the check (#567). Scrolling the window to its top first does not always stick.
+    await page.goto('about:blank');
+    await page.goto(route);
     await expect(rows(page)).toHaveCount(100);
     // D183: the end of the list arrives inside the tag window.
     const scroll=top=>main(page).locator('.two-col .table-wrap').evaluate((node,y)=>new Promise(resolve=>{node.scrollTop=y ?? node.scrollHeight;requestAnimationFrame(()=>requestAnimationFrame(resolve));}),top);

tests/comfyui/prompt-sender.spec.mjs

@@ -131,11 +131,40 @@ test('native image inspector previews and sends a pair into real visible widgets
         const twinId=await page.evaluate(async()=>{const {app}=await import('/scripts/app.js');const node=LiteGraph.createNode('PromptManagerPair');app.graph.add(node);return node.id;});
         await find0.click();
         const targets=sender.getByRole('combobox',{name:'Destination node',exact:true});
-        await expect(targets.locator('option')).toHaveCount(3);
+        await expect(targets.locator('option')).toHaveCount(4);
         await expect(targets).toHaveValue('');
         await expect(apply).toBeDisabled();
         await expect(targets.locator('option').nth(2)).toHaveText(new RegExp(`^#${twinId} `));
-        await page.evaluate(async twinId=>{const {app}=await import('/scripts/app.js');app.graph.remove(app.graph.getNodeById(twinId));},twinId);
+        // #542 D191: "All 2 eligible nodes" writes both real nodes, one after another; a linked third node is not offered.
+        const linkedId=await page.evaluate(async()=>{
+            const {app}=await import('/scripts/app.js');const {convertToInput}=await import('/extensions/core/widgetInputs.js');
+            const node=LiteGraph.createNode('PromptManagerPair');app.graph.add(node);
+            const widget=node.widgets.find(widget=>widget.name==='text');
+            if(!node.inputs.some(input=>input.name==='text'))convertToInput(node,widget);
+            const source=LiteGraph.createNode('PrimitiveString');app.graph.add(source);
+            source.connect(0,node,node.inputs.findIndex(input=>input.name==='text'));
+            for(const each of app.graph._nodes.filter(item=>item.type==='PromptManagerPair')){const text=each.widgets.find(widget=>widget.name==='text');if(text)text.value=`Before all ${each.id}`;}
+            return node.id;
+        });
+        await find0.click();
+        await expect(targets.locator('option')).toHaveText(['Choose a destination node',new RegExp(`^#${id} `),new RegExp(`^#${twinId} `),'All 2 eligible nodes']);
+        await expect(sender.getByRole('status')).toContainText('1 other Prompt Manager node cannot receive this prompt.');
+        await targets.selectOption({label:'All 2 eligible nodes'});
+        await sender.getByRole('button',{name:'Preview changes',exact:true}).click();
+        await expect(sender.locator('section.prompt-sender-node > h4')).toHaveText([new RegExp(`^#${id} `),new RegExp(`^#${twinId} `)]);
+        await apply.click();
+        // The tab title gains ComfyUI's unsaved mark once the workflow changed, so the window is matched loosely.
+        await expect(sender.getByRole('status')).toHaveText(/^Sent to 2 of 2 nodes in .*ComfyUI\.$/);
+        await expect(apply).toBeDisabled();
+        const all=await page.evaluate(async ids=>{
+            const {app}=await import('/scripts/app.js');const output=(await app.graphToPrompt()).output;
+            return ids.map(nodeId=>{const node=app.graph.getNodeById(nodeId);const serialized=node.serialize();const index=node.widgets.findIndex(widget=>widget.name==='negative_text');
+                return{prompt:output[String(nodeId)]?.inputs.negative_text,serialized:serialized.widgets_values[index],text:node.widgets.find(widget=>widget.name==='text')?.value};});
+        },[id,twinId,linkedId]);
+        expect(all.slice(0,2)).toEqual([{prompt:negative,serialized:negative,text:positive},{prompt:negative,serialized:negative,text:positive}]);
+        expect(all[2].text).toBe(`Before all ${linkedId}`);
+        expect(await page.evaluate(()=>window.senderEffects.queue-window.senderSendBaseline.queue)).toBe(0);
+        await page.evaluate(async ids=>{const {app}=await import('/scripts/app.js');for(const nodeId of ids)app.graph.remove(app.graph.getNodeById(nodeId));},[twinId,linkedId]);
         // #535: the status line says why a window cannot receive.
         const find=sender.getByRole('button',{name:'Find ComfyUI windows',exact:true});
         const preview=sender.getByRole('button',{name:'Preview changes',exact:true});

tests/fixtures/legacy_contract_snapshot.json

@@ -212,6 +212,12 @@
     "thumbnail_encoders",
     "thumbnail_encoders.jpeg",
     "thumbnail_encoders.jxl",
-    "thumbnail_encoders.webp"
+    "thumbnail_encoders.webp",
+    "thumbnail_location",
+    "thumbnail_location.available",
+    "thumbnail_location.default_path",
+    "thumbnail_location.mode",
+    "thumbnail_location.path",
+    "thumbnail_location.problem"
   ]
 }

tests/js/legacy-refusals.test.js

@@ -21,14 +21,6 @@ function jsonResponse(status, body) {
         json: async () => body };
 }
 
-function sseResponse(frames) {
-    const bytes = new TextEncoder().encode(frames.map(frame => `data: ${JSON.stringify(frame)}\n\n`).join(''));
-    let sent = false;
-    return { ok: true, status: 200, body: { getReader: () => ({
-        read: async () => (sent ? { done: true } : (sent = true, { done: false, value: bytes })),
-    }) } };
-}
-
 function load(file, className, fetchUrl, extra = {}, dom = elements()) {
     const timers = [];
     const notifications = [];
@@ -63,8 +55,6 @@ function load(file, className, fetchUrl, extra = {}, dom = elements()) {
     return { page, dom, timers, notifications, storage };
 }
 
-const BUSY = 'Scan for metadata already running';
-
 test('admin settings save shows why config.json refused it', async () => {
     const message = 'config.json cannot be read, so nothing was saved. Fix or remove the file, then save again.';
     const { page, notifications } = load('admin.js', 'PromptAdmin',

tests/js/prompt-sender.test.js

@@ -225,3 +225,141 @@ test('acknowledgement cannot claim an extra role beyond approved changes',async(
     const {createSendSession}=await source;const s=setup(createSendSession,{apply:async()=>({targetId:'one',values:{positive:'new',negative:'also changed'}})});
     await s.session.discover();s.session.selectHost('host');s.session.selectTarget('one');await s.session.preview();await s.session.apply();assert.equal(s.session.state.phase,'error');assert.match(s.session.state.message,/unexpected acknowledgement/);s.session.dispose();
 });
+// #542: "All N eligible nodes" sends to every eligible node of one window, previewing every node first (Q542-2 C).
+function allHost({nodes=['10','9','2'],revision,preview,apply,discover}={}) {
+    const calls=[];const sent=new Set();
+    const targets=nodes.map(id=>pm(id,['positive'],revision?{revision}:{}));
+    const client={
+        discover:discover ?? (async()=>[window1(targets)]),
+        preview:async(host,id,roles)=>{calls.push(['preview',id]);if(preview)return preview(id,calls,sent);return{ticket:`t-${id}-${calls.length}`,revision,target:{id,label:`Node ${id}`},fields:[{role:'positive',before:sent.has(id)?'new':'old',after:roles.positive}]};},
+        apply:async(host,ticket)=>{const id=ticket.split('-')[1];calls.push(['apply',id,ticket]);if(apply)return apply(id,calls);sent.add(id);return{targetId:id,values:{positive:'new'}};},
+        dispose:()=>calls.push(['dispose']),
+    };
+    return {client,calls,sent};
+}
+async function allSession(createSendSession,options) {
+    const host=allHost(options);const session=createSendSession({client:host.client,roles:{positive:'new'},onChange:()=>{}});
+    await session.discover();return {...host,session};
+}
+const order=calls=>calls.filter(call=>call[0]!=='dispose').map(call=>`${call[0]} ${call[1]}`);
+test('All is offered only with two or more eligible nodes and is never selected for you',async()=>{
+    const {createSendSession,ALL_NODES}=await source;
+    const one=await allSession(createSendSession,{nodes:['1']});
+    one.session.selectTarget(ALL_NODES);assert.equal(one.session.state.targetId,'');assert.equal(one.calls.length,0);one.session.dispose();
+    const two=await allSession(createSendSession,{nodes:['1','2']});
+    assert.equal(two.session.state.targetId,'');
+    two.session.selectTarget(ALL_NODES);assert.equal(two.session.state.targetId,ALL_NODES);
+    assert.match(two.session.state.message,/all 2 eligible nodes in Flow - ComfyUI/);
+    await two.session.discover();assert.equal(two.session.state.targetId,'');two.session.dispose();
+});
+test('Apply to All previews every node first, then sends one after another in node id order',async()=>{
+    const {createSendSession,ALL_NODES}=await source;const s=await allSession(createSendSession);
+    s.session.selectTarget(ALL_NODES);await s.session.apply();
+    assert.deepEqual(order(s.calls),['preview 2','preview 9','preview 10','apply 2','preview 9','apply 9','preview 10','apply 10']);
+    assert.equal(s.session.state.phase,'success');assert.equal(s.session.state.message,'Sent to 3 of 3 nodes in Flow - ComfyUI.');
+    await s.session.apply();assert.equal(s.calls.filter(call=>call[0]==='apply').length,3);s.session.dispose();
+});
+test('a double click on Apply to All sends to each node once',async()=>{
+    const {createSendSession,ALL_NODES}=await source;const s=await allSession(createSendSession,{nodes:['1','2']});
+    s.session.selectTarget(ALL_NODES);await Promise.all([s.session.apply(),s.session.apply()]);
+    assert.deepEqual(s.calls.filter(call=>call[0]==='apply').map(call=>call[1]),['1','2']);s.session.dispose();
+});
+test('a node refusing its preview stops All before anything is written and names the node',async()=>{
+    const {createSendSession,ALL_NODES}=await source;
+    const s=await allSession(createSendSession,{preview:id=>{if(id==='9')throw Error('positive is connected to an upstream input.');return{ticket:`t-${id}`,target:{id},fields:[{role:'positive',before:'old',after:'new'}]};}});
+    s.session.selectTarget(ALL_NODES);await s.session.apply();
+    assert.equal(s.calls.filter(call=>call[0]==='apply').length,0);assert.equal(s.session.state.phase,'error');
+    assert.match(s.session.state.message,/^#9 Node 9: positive is connected to an upstream input\. Nothing was sent\./);
+    assert.equal(s.session.state.outcomeUnknown,false);s.session.dispose();
+});
+test('a refusal while sending to All is reported by node and the other nodes are still sent',async()=>{
+    const {createSendSession,ALL_NODES}=await source;
+    const s=await allSession(createSendSession,{apply:id=>{if(id==='9')throw Error('Workflow or prompt changed. Preview again.');return{targetId:id,values:{positive:'new'}};}});
+    s.session.selectTarget(ALL_NODES);await s.session.apply();
+    assert.deepEqual(s.calls.filter(call=>call[0]==='apply').map(call=>call[1]),['2','9','10']);
+    assert.equal(s.session.state.phase,'error');assert.equal(s.session.state.outcomeUnknown,false);
+    assert.equal(s.session.state.message,'Sent to 2 of 3 nodes in Flow - ComfyUI. #9 Node 9: Workflow or prompt changed. Preview again.');s.session.dispose();
+});
+test('a lost reply on one node of All leaves the later nodes unsent and that outcome unknown',async()=>{
+    const {createSendSession,ALL_NODES}=await source;
+    const s=await allSession(createSendSession,{apply:id=>{if(id==='9')throw Error('Bridge request timed out');return{targetId:id,values:{positive:'new'}};}});
+    s.session.selectTarget(ALL_NODES);await s.session.apply();
+    assert.deepEqual(s.calls.filter(call=>call[0]==='apply').map(call=>call[1]),['2','9']);
+    assert.equal(s.session.state.outcomeUnknown,true);
+    assert.match(s.session.state.message,/^Sent to 1 of 3 nodes in Flow - ComfyUI\. No confirmation received from #9 Node 9; the update may have applied\. Not sent: #10 Node 10\. Check ComfyUI, then preview again\. Bridge request timed out$/);
+    await s.session.apply();assert.equal(s.calls.filter(call=>call[0]==='apply').length,2);s.session.dispose();
+});
+test('closing the dialog during All stops after the current node',async()=>{
+    const {createSendSession,ALL_NODES}=await source;let release;
+    const s=await allSession(createSendSession,{apply:id=>id==='2'?new Promise(done=>release=()=>done({targetId:id,values:{positive:'new'}})):{targetId:id,values:{positive:'new'}}});
+    s.session.selectTarget(ALL_NODES);const pending=s.session.apply();
+    for(let i=0;i<50 && !release;i++)await tick();assert.ok(release,'the first node was sent');
+    s.session.dispose();release();await pending;
+    assert.deepEqual(s.calls.filter(call=>call[0]==='apply').map(call=>call[1]),['2']);
+});
+test('All accepts the revision our own write moved, but not a workflow changed before the run',async()=>{
+    const {createSendSession,ALL_NODES}=await source;
+    // The host moves the graph version on every write: later nodes preview with the new revision.
+    let version=4;
+    const bumped=await allSession(createSendSession,{revision:'1:4',preview:id=>({ticket:`t-${id}`,revision:`1:${version}`,target:{id},fields:[{role:'positive',before:'old',after:'new'}]}),apply:id=>{version++;return{targetId:id,values:{positive:'new'}};}});
+    bumped.session.selectTarget(ALL_NODES);await bumped.session.apply();
+    assert.equal(bumped.session.state.message,'Sent to 3 of 3 nodes in Flow - ComfyUI.');bumped.session.dispose();
+    const moved=await allSession(createSendSession,{revision:'1:4',preview:id=>({ticket:`t-${id}`,revision:'1:5',target:{id},fields:[{role:'positive',before:'old',after:'new'}]})});
+    moved.session.selectTarget(ALL_NODES);await moved.session.apply();
+    assert.match(moved.session.state.message,/workflow changed since this window was found/i);assert.equal(moved.calls.filter(call=>call[0]==='apply').length,0);moved.session.dispose();
+});
+test('a node whose text changed after the preview pass is refused, not overwritten',async()=>{
+    const {createSendSession,ALL_NODES}=await source;let edited=false;
+    const s=await allSession(createSendSession,{preview:id=>({ticket:`t-${id}`,target:{id},fields:[{role:'positive',before:id==='10'&&edited?'typed in ComfyUI':'old',after:'new'}]}),apply:id=>{edited=true;return{targetId:id,values:{positive:'new'}};}});
+    s.session.selectTarget(ALL_NODES);await s.session.apply();
+    assert.deepEqual(s.calls.filter(call=>call[0]==='apply').map(call=>call[1]),['2','9']);
+    assert.match(s.session.state.message,/^Sent to 2 of 3 nodes in Flow - ComfyUI\. #10 Node 10: Its prompt changed since the preview\./);s.session.dispose();
+});
+test('Preview with All shows every node in order, and Apply sends fresh tickets that match the review',async()=>{
+    const {createSendSession,ALL_NODES}=await source;const s=await allSession(createSendSession);
+    s.session.selectTarget(ALL_NODES);await s.session.preview();
+    assert.equal(s.session.state.phase,'ready');assert.equal(s.session.state.preview,null);
+    assert.deepEqual(s.session.state.previews.map(item=>item.label),['#2 Node 2','#9 Node 9','#10 Node 10']);
+    assert.match(s.session.state.message,/Sending to all 3 eligible nodes in Flow - ComfyUI\. Review the complete changes, then apply\./);
+    const first=s.session.state.previews[0].preview.ticket;
+    await s.session.apply();
+    // A held review may have outlived the host's 30 s tickets, so even the first node takes a fresh one.
+    assert.deepEqual(order(s.calls),['preview 2','preview 9','preview 10','preview 2','apply 2','preview 9','apply 9','preview 10','apply 10']);
+    assert.notEqual(s.calls.find(call=>call[0]==='apply')[2],first);assert.equal(s.session.state.phase,'success');
+    s.session.selectTarget('2');assert.deepEqual(s.session.state.previews,[]);s.session.dispose();
+});
+test('the dialog offers All for two or more nodes and reviews each node under its name',async()=>{
+    const {createPromptSender,ALL_NODES}=await source;const {createScope}=await import('../../web/js/shared/toolkit/core.js');
+    const dom=fakeDOM();const scope=createScope();
+    const {client}=allHost({nodes:['1','2']});
+    try {
+        createPromptSender({scope,clientFactory:()=>client}).open({positive:'new'});await tick();
+        const dialog=dom.body.children.at(-1);const target=dom.find(dialog,node=>node.id==='prompt-sender-target');
+        assert.deepEqual(target.children.map(option=>[option.value,option.textContent]),[['','Choose a destination node'],['1','#1 Node 1'],['2','#2 Node 2'],[ALL_NODES,'All 2 eligible nodes']]);
+        assert.equal(target.value,'');target.value=ALL_NODES;target.dispatchEvent(new Event('change'));
+        dom.find(dialog,node=>node.textContent==='Preview changes').dispatchEvent(new Event('click'));for(let i=0;i<5;i++)await tick();
+        const sections=[];(function walk(node){if(node.className==='prompt-sender-node')sections.push(node);node.children.forEach(walk);})(dialog);
+        assert.deepEqual(sections.map(section=>section.children[0].textContent),['#1 Node 1','#2 Node 2']);
+        dom.find(dialog,node=>node.textContent==='Apply to ComfyUI').dispatchEvent(new Event('click'));for(let i=0;i<10;i++)await tick();
+        assert.ok(dom.find(dialog,node=>node.textContent==='Sent to 2 of 2 nodes in Flow - ComfyUI.'));
+    } finally {scope.dispose();dom.restore();}
+});
+test('an expired review still sends every node, and a held review checks the discovered revision first',async()=>{
+    const {createSendSession,ALL_NODES}=await source;let reviewing=true;
+    // The host refuses every ticket taken during the review, as after its 30 s expiry.
+    const s=await allSession(createSendSession,{preview:(id,calls)=>({ticket:`t-${id}-${reviewing?'old':calls.length}`,target:{id},fields:[{role:'positive',before:'old',after:'new'}]}),apply:id=>({targetId:id,values:{positive:'new'}})});
+    const realApply=s.client.apply;s.client.apply=async(host,ticket,options)=>{if(ticket.endsWith('-old'))throw Error('Preview expired or unavailable; preview again');return realApply(host,ticket,options);};
+    s.session.selectTarget(ALL_NODES);await s.session.preview();reviewing=false;await s.session.apply();
+    assert.equal(s.session.state.message,'Sent to 3 of 3 nodes in Flow - ComfyUI.');s.session.dispose();
+    const moved=await allSession(createSendSession,{revision:'1:4',preview:(id,calls)=>({ticket:`t-${id}`,revision:calls.length>3?'1:5':'1:4',target:{id},fields:[{role:'positive',before:'old',after:'new'}]})});
+    moved.session.selectTarget(ALL_NODES);await moved.session.preview();assert.equal(moved.session.state.phase,'ready');await moved.session.apply();
+    assert.match(moved.session.state.message,/^Sent to 0 of 3 nodes in Flow - ComfyUI\. #2 Node 2: The workflow changed since this window was found/);
+    assert.equal(moved.calls.filter(call=>call[0]==='apply').length,0);moved.session.dispose();
+});
+test('a changed prepend or append after the review refuses that node',async()=>{
+    const {createSendSession,ALL_NODES}=await source;let edited=false;
+    const s=await allSession(createSendSession,{preview:id=>({ticket:`t-${id}`,target:{id},fields:[{role:'positive',before:'old',after:'new'}],composition:{prepend:id==='9'&&edited?'typed':'trigger',append:'',before:'trigger old',after:'trigger new'}}),apply:id=>{edited=true;return{targetId:id,values:{positive:'new'}};}});
+    s.session.selectTarget(ALL_NODES);await s.session.apply();
+    assert.deepEqual(s.calls.filter(call=>call[0]==='apply').map(call=>call[1]),['2','10']);
+    assert.match(s.session.state.message,/^Sent to 2 of 3 nodes in Flow - ComfyUI\. #9 Node 9: Its prompt changed since the preview\./);s.session.dispose();
+});

tests/js/workspace-system-backups.test.js

@@ -128,6 +128,24 @@ test('invalid file shows the validator message; a refusal names its job; a lost
     assert.deepEqual(await uploadRestore(file, { ApiError, fetchUrl: async () => response(200, PREVIEW) }), PREVIEW);
 });
 
+// #583: WebKit reads a FormData's file part by reference, possibly after a garbage collection; the page holds the form
+// until the upload is answered, then lets it go, whether the server staged it, refused it or the request failed.
+test('a review upload keeps its form referenced until the upload is answered', async () => {
+    const { uploadRestore, uploadsInFlight } = await backups;
+    const file = new File(['bytes'], 'b.db');
+    for (const answer of [async () => response(200, PREVIEW), async () => response(400, { success: false, error: 'x' }),
+        async () => { throw new TypeError('offline'); }]) {
+        let held;
+        const upload = uploadRestore(file, { ApiError, fetchUrl: async (url, init) => {
+            held = uploadsInFlight.has(init.body) && init.body.get('database_file').size === file.size;
+            return answer();
+        } }).catch(() => {});
+        await upload;
+        assert.equal(held, true);
+        assert.equal(uploadsInFlight.size, 0);
+    }
+});
+
 test('Cancel discards the stage through the api client and never throws', async () => {
     const { discardRestore, PREVIEW_URL } = await backups;
     const calls = [];

tests/js/workspace-system-overview.test.js

@@ -16,12 +16,22 @@ const OVERVIEW = Object.freeze({
 
 test('metrics are the server counts and Not checked before any health check', async () => {
     const { metricValues } = await overviewModule;
-    assert.deepEqual(metricValues(OVERVIEW), [
+    assert.deepEqual(metricValues(OVERVIEW, 24), [
         [(1234).toLocaleString(), 'Positive prompts'], ['7', 'Negative variants'], ['24', 'Images'],
         ['Not checked', 'Database integrity'],
     ]);
 });
 
+test('#555: the Images metric is the Images page count (the sidebar badge), not the indexed rows', async () => {
+    const { metricValues } = await overviewModule;
+    // The demo library: 110 indexed rows, 122 files on the Images page (unlinked ones included).
+    const overview = { ...OVERVIEW, images: { indexed: 110, rated: 0 } };
+    assert.deepEqual(metricValues(overview, 122)[2], [(122).toLocaleString(), 'Images']);
+    // Not read yet (undefined) or failed (null): a dash, as on the workspace Overview, never the row count.
+    assert.deepEqual(metricValues(overview, undefined)[2], ['–', 'Images']);
+    assert.deepEqual(metricValues(overview, null)[2], ['–', 'Images']);
+});
+
 test('metric 4 is the last health result', async () => {
     const { integrityText } = await overviewModule;
     assert.equal(integrityText(null), 'Not checked');
@@ -150,7 +160,7 @@ test('statistics rows are the real runs, then the library totals, without rating
         rated_images: 20,
     };
     assert.deepEqual(categoryRows(statistics), [['Landscapes', (1200).toLocaleString()], ['Uncategorized', '3']]);
-    assert.deepEqual(totalsRows(statistics), [['Prompts', '12'], ['Tags', '15'], ['Images', '24']]);
+    assert.deepEqual(totalsRows(statistics), [['Prompt records', '12'], ['Tags on prompts', '15'], ['Image records', '24']]);
 });
 
 /** A fake api answering each `get`/`post` from a queue per URL, recording the calls. */

tests/test_api_admin.py

@@ -2584,7 +2584,7 @@ class TestActivityJobs(AdminAPITestCase):
     async def test_cancel_after_first_batch_keeps_partial_counts(self):
         """Review M7: the real scan stops at the batch boundary, keeping batch 1."""
         import threading
-        from unittest import mock
+        import unittest.mock as mock
 
         from py.api import admin
 

tests/test_api_autotag.py

@@ -600,6 +600,33 @@ class TestAutotagSingleEdgeCases(AutotagAPITestCase):
             {"path": str(image), "general_threshold": "high"},
         )
         self.assertEqual(resp.status, 400)
+        self.assertEqual(
+            (await resp.json())["error"],
+            "general_threshold and character_threshold must be numeric",
+        )
+
+    async def test_invalid_single_options_report_the_validation_error(self) -> None:
+        image = self._make_image(self.output_dir)
+        cases = (
+            (
+                {"model_type": "wd14-vit", "general_threshold": 2},
+                "general_threshold must be between 0 and 1",
+            ),
+            (
+                {"model_type": "gguf", "prompt": "x" * 4001},
+                "instructions must be at most 4000 characters",
+            ),
+        )
+        for options, message in cases:
+            with self.subTest(options=options["model_type"]):
+                resp = await self._post_json(
+                    "/prompt_manager/autotag/single",
+                    {"path": str(image), **options},
+                )
+                self.assertEqual(resp.status, 400)
+                self.assertEqual(
+                    await resp.json(), {"success": False, "error": message}
+                )
 
     async def test_prompt_lookup_failure_still_returns_tags(self):
         image = self._make_image(self.output_dir)
@@ -1151,7 +1178,9 @@ class TestModelStatus(AutotagAPITestCase):
         )
         # Kept fields legacy pages and the workspace read.
         for model in models.values():
-            self.assertTrue({"name", "description", "size", "downloaded"} <= set(model))
+            self.assertLessEqual(
+                {"name", "description", "size", "downloaded"}, set(model)
+            )
         self.assertTrue(data["model_loaded"])
         self.assertEqual(data["loaded_model_type"], "wd14-vit")
 

tests/test_api_core.py

@@ -351,8 +351,6 @@ class TestLongJobLock(unittest.TestCase):
         self.api = PromptManagerAPI(db=database)
 
     def _run(self, coro):
-        import asyncio
-
         return asyncio.run(coro)
 
     def test_second_acquire_is_refused_until_first_releases(self):
@@ -825,8 +823,6 @@ class TestInstanceHelpers(FolderPathsFixture):
         self.addCleanup(setattr, GalleryConfig, "MONITORING_DIRECTORIES", orig_dirs)
 
     def _run(self, coro):
-        import asyncio
-
         return asyncio.run(coro)
 
     def test_run_in_executor_with_kwargs(self):

tests/test_api_diagnostics_report.py

@@ -16,7 +16,7 @@ import re
 import sqlite3
 import sys
 import unittest
-from unittest import mock
+import unittest.mock as mock
 from unittest.mock import MagicMock
 
 _mock_server = MagicMock()

tests/test_api_duplicate_safety.py

@@ -381,7 +381,7 @@ class TestAnotherMount(SafetyTestCase):
         self.assertTrue(other.is_file() and keeper.is_file())
 
     async def test_a_volume_without_file_ids_is_named_truthfully(self):
-        keeper, other, patches = self.mount("x.png", "x.png")
+        self.mount("x.png", "x.png")
 
         def zero(path, *args, **kwargs):
             return _fake_stat(self.real_stat(path), st_dev=0, st_ino=0)

tests/test_api_images.py

@@ -3713,7 +3713,7 @@ class TestSharedListing(ImageAPITestCase):
 
     async def test_a_root_read_again_after_the_roots_change_listens_again(self):
         make_png(self.output_dir / "a.png")
-        record = await self._listed()
+        await self._listed()
         self.api.reset_gallery_roots_cache()
         record = await self._listed()  # still configured: read and walked
         self._interval(0)

tests/test_api_lora.py

@@ -840,6 +840,23 @@ class TestLoraScanRoute(LoraAPITestCase):
             ("error", error["message"], 0),
         )
 
+    async def test_unexpected_scan_error_is_generic_in_the_stream(self):
+        self._enable()
+        secret = str(self.tmp_root / "x.db")
+        err = RuntimeError(f"could not open {secret}")
+        with patch.object(self.api.db, "replace_category_prompts", side_effect=err):
+            with self.assertLogs("prompt_manager.api", level="ERROR") as logs:
+                resp = await self.client.request("POST", "/prompt_manager/lora/scan")
+                body = await resp.text()  # the stream ends inside the patch
+        self.assertNotIn("x.db", body)
+        error = self._sse_events(body)[-1]
+        self.assertEqual(
+            (error["type"], error["status"], error["progress"]),
+            ("error", error["message"], 0),
+        )
+        self.assertIn("server log", error["message"])
+        self.assertIn(secret, "\n".join(logs.output))
+
     @staticmethod
     def _sse_events(text):
         return [

tests/test_api_maintenance.py

@@ -675,7 +675,7 @@ class TestBackupPoolAndDiskSpace(ApplyTestCase):
         self.assertEqual(len(backups), MAX_SAFETY_BACKUPS)
         self.assertNotIn(restore_style[0], backups)
         self.assertNotIn(restore_style[1], backups)
-        self.assertTrue(set(maintenance_style) <= set(backups))
+        self.assertLessEqual(set(maintenance_style), set(backups))
         # A restore prunes the same pool, maintenance backups included.
         self.old_backup("prompts.db.backup_20020101_000000", 3000)
         _prune_safety_backups(self.api.db.model.db_path)

tests/test_api_thumbnail_location.py

@@ -0,0 +1,415 @@
+"""The thumbnail location setting (#320 PR 2): parsing, validation, source
+keys, the marker, the settings payloads and reverse containment.
+
+Spelling rules are tested on both path flavors (``ntpath`` and
+``posixpath``) as text; filesystem rules run on the native one.
+"""
+
+import json
+import ntpath
+import os
+import posixpath
+import re
+import sys
+import tempfile
+import threading
+import unittest
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+sys.modules.setdefault("server", MagicMock())
+
+from py.api import preview_location as pl  # noqa: E402
+from py.api import preview_store  # noqa: E402
+
+REPO = Path(__file__).resolve().parent.parent
+
+
+class TestParse(unittest.TestCase):
+    def test_missing_or_source_is_inside_each_source(self):
+        for value in (None, {"mode": "source"}, {}):
+            with self.subTest(value=value):
+                parsed = pl.parse_location(value)
+                self.assertEqual((parsed.mode, parsed.problem), ("source", None))
+
+    def test_a_folder_location_is_kept_as_spelled(self):
+        parsed = pl.parse_location(
+            {"mode": "folder", "path": "D:\\Thumbs", "id": "x", "install": "i"},
+            flavor=ntpath,
+        )
+        self.assertEqual(
+            (parsed.mode, parsed.path, parsed.id, parsed.problem),
+            ("folder", "D:\\Thumbs", "x", None),
+        )
+
+    def test_invalid_values_never_fall_back_to_the_sources(self):
+        for value in (
+            "folder",
+            {"mode": "elsewhere"},
+            {"mode": "folder", "path": "relative", "id": "x"},
+            {"mode": "folder", "path": "/abs"},
+            {"mode": "folder", "path": "/abs", "id": ""},
+            {"mode": "folder", "path": 7, "id": "x"},
+        ):
+            with self.subTest(value=value):
+                parsed = pl.parse_location(value, flavor=posixpath)
+                self.assertEqual((parsed.mode, parsed.problem), ("folder", "invalid"))
+
+
+class TestForm(unittest.TestCase):
+    def test_windows_spellings(self):
+        cases = {
+            "D:\\Thumbs": None,
+            "\\\\server\\share\\thumbs": None,
+            "C:thumbs": "location-not-absolute",
+            "\\thumbs": "location-not-absolute",
+            "thumbs": "location-not-absolute",
+            "": "location-not-absolute",
+            " D:\\Thumbs": "location-not-absolute",
+            "\\\\?\\D:\\Thumbs": "location-device-path",
+            "\\\\.\\D:\\Thumbs": "location-device-path",
+            "D:\\CON\\x": "location-invalid-name",
+            "D:\\com1.txt": "location-invalid-name",
+            "D:\\thumbs.": "location-invalid-name",
+            "D:\\thumbs ": "location-invalid-name",
+            "D:\\a|b": "location-invalid-name",
+            "D:\\a?b": "location-invalid-name",
+            "D:\\a\x01b": "location-invalid-name",
+        }
+        for path, code in cases.items():
+            with self.subTest(path=path):
+                self.assertEqual(pl.form_problem(path, flavor=ntpath), code)
+
+    def test_posix_spellings(self):
+        cases = {
+            "/mnt/fast/thumbs": None,
+            "mnt/thumbs": "location-not-absolute",
+            "/mnt/nul": "location-invalid-name",
+            "/mnt/a:b": "location-invalid-name",
+            "//?/x": "location-device-path",
+        }
+        for path, code in cases.items():
+            with self.subTest(path=path):
+                self.assertEqual(pl.form_problem(path, flavor=posixpath), code)
+
+    def test_roots_and_home_are_too_broad(self):
+        self.assertTrue(pl.is_too_broad("C:\\", home="C:\\Users\\a", flavor=ntpath))
+        self.assertTrue(
+            pl.is_too_broad("\\\\server\\share", home="C:\\Users\\a", flavor=ntpath)
+        )
+        self.assertTrue(
+            pl.is_too_broad("C:\\users\\A", home="C:\\Users\\a", flavor=ntpath)
+        )
+        self.assertTrue(pl.is_too_broad("/", home="/home/a", flavor=posixpath))
+        self.assertTrue(pl.is_too_broad("/home/a/", home="/home/a", flavor=posixpath))
+        self.assertFalse(
+            pl.is_too_broad("/home/a/thumbs", home="/home/a", flavor=posixpath)
+        )
+
+    def test_long_windows_paths_are_refused_without_long_paths(self):
+        short = "D:\\" + "a" * 100
+        long = "D:\\" + "a" * 200
+        self.assertFalse(pl.too_long_for_windows(short, long_paths=False))
+        self.assertTrue(pl.too_long_for_windows(long, long_paths=False))
+        self.assertFalse(pl.too_long_for_windows(long, long_paths=True))
+
+
+class TestSourceKeys(unittest.TestCase):
+    def test_slug(self):
+        self.assertEqual(pl.slug("ComfyUI Output"), "comfyui-output")
+        self.assertEqual(pl.slug("Ünïcödé_Fôlder"), "unicode_folder")
+        self.assertEqual(pl.slug(""), "source")
+        self.assertEqual(pl.slug("!!!"), "source")
+        self.assertEqual(len(pl.slug("x" * 80)), 24)
+
+    def test_keys_are_a_slug_plus_a_hash(self):
+        key = pl.source_key("D:\\AI\\Output", "d:\\ai\\output", {})
+        self.assertRegex(key, r"^output-[0-9a-f]{8}$")
+        self.assertRegex(pl.source_key("D:\\", "d:\\", {}), r"^source-[0-9a-f]{8}$")
+        self.assertRegex(
+            pl.source_key("\\\\nas\\share\\Out", "\\\\nas\\share\\out", {}),
+            r"^out-[0-9a-f]{8}$",
+        )
+
+    def test_a_taken_key_grows_its_hash(self):
+        first = pl.source_key("/a/out", "/a/out", {})
+        taken = {first: "/someone/else"}
+        second = pl.source_key("/a/out", "/a/out", taken)
+        self.assertRegex(second, r"^out-[0-9a-f]{12}$")
+        taken[second] = "/another"
+        self.assertRegex(
+            pl.source_key("/a/out", "/a/out", taken), r"^out-[0-9a-f]{16}$"
+        )
+        self.assertEqual(pl.source_key("/a/out", "/a/out", {first: "/a/out"}), first)
+
+    def test_lookup_by_spelling_identity_then_file_id(self):
+        keys = {
+            "out-0123abcd": {
+                "path": "D:\\Out",
+                "identity": "d:\\out",
+                "dev_ino": [1, 2],
+            },
+            "lib-0123abcd": {"path": "E:\\Lib", "identity": "e:\\lib", "dev_ino": None},
+        }
+        self.assertEqual(pl.find_key(keys, "D:\\Out", "x", None), "out-0123abcd")
+        self.assertEqual(pl.find_key(keys, "Z:\\Out", "d:\\out", None), "out-0123abcd")
+        # A letter spelling and its UNC spelling: the same file id.
+        self.assertEqual(
+            pl.find_key(keys, "\\\\nas\\out", "\\\\nas\\out", (1, 2)), "out-0123abcd"
+        )
+        self.assertIsNone(pl.find_key(keys, "F:\\New", "f:\\new", (9, 9)))
+
+
+class TestMarker(unittest.TestCase):
+    def setUp(self):
+        self._tmp = tempfile.TemporaryDirectory()
+        self.addCleanup(self._tmp.cleanup)
+        self.folder = self._tmp.name
+
+    def test_init_creates_once_and_adopts_after(self):
+        first = pl.init_folder(self.folder, created_by_pm=True)
+        self.assertEqual(pl.init_folder(self.folder), first)
+        marker = pl.read_marker(self.folder)
+        self.assertEqual(marker["id"], first)
+        self.assertTrue(marker["created_by_pm"])
+        self.assertEqual(marker["version"], 1)
+
+    def test_writes_merge_what_another_writer_added(self):
+        pl.init_folder(self.folder)
+        pl.write_marker(
+            self.folder, lambda m: m["keys"].update({"a-0123abcd": {"install": "1"}})
+        )
+        pl.write_marker(
+            self.folder, lambda m: m["keys"].update({"b-0123abcd": {"install": "2"}})
+        )
+        self.assertEqual(
+            sorted(pl.read_marker(self.folder)["keys"]), ["a-0123abcd", "b-0123abcd"]
+        )
+        # No temp file is left beside it.
+        self.assertEqual(os.listdir(self.folder), [pl.MARKER_NAME])
+
+    def test_a_folder_without_the_marker_is_missing(self):
+        self.assertEqual(pl.folder_state(self.folder, "x")[:2], (False, "missing"))
+        missing = os.path.join(self.folder, "gone")
+        self.assertEqual(pl.folder_state(missing, "x")[:2], (False, "missing"))
+        marker_id = pl.init_folder(self.folder)
+        self.assertEqual(pl.folder_state(self.folder, marker_id)[:2], (True, None))
+        self.assertEqual(
+            pl.folder_state(self.folder, "other")[:2], (False, "marker-mismatch")
+        )
+
+    @unittest.skipUnless(hasattr(os, "symlink"), "needs symlinks")
+    def test_a_linked_folder_is_not_available(self):
+        real = os.path.join(self.folder, "real")
+        os.mkdir(real)
+        marker_id = pl.init_folder(real)
+        link = os.path.join(self.folder, "link")
+        try:
+            os.symlink(real, link, target_is_directory=True)
+        except OSError:
+            self.skipTest("symlinks not permitted")
+        self.assertEqual(pl.folder_state(link, marker_id)[:2], (False, "invalid"))
+
+
+class TestValidation(unittest.TestCase):
+    def setUp(self):
+        self._tmp = tempfile.TemporaryDirectory()
+        self.addCleanup(self._tmp.cleanup)
+        self.base = os.path.realpath(self._tmp.name)
+        self.source = os.path.join(self.base, "output")
+        self.node = os.path.join(self.base, "node")
+        os.mkdir(self.source)
+        os.mkdir(self.node)
+        self.context = pl.Context(
+            roots=(self.source,),
+            node_folder=self.node,
+            default_path=os.path.join(self.node, "data", "thumbnails"),
+            home=os.path.join(self.base, "home"),
+            environ={},
+            long_paths=True,
+            folder_paths=None,
+        )
+
+    def problem(self, path, purpose="move", **changes):
+        context = self.context
+        if changes:
+            context = pl.Context(**{**context.__dict__, **changes})
+        return pl.location_problem(path, purpose=purpose, context=context)
+
+    def test_an_empty_new_folder_beside_the_sources_is_accepted(self):
+        self.assertIsNone(self.problem(os.path.join(self.base, "thumbs")))
+        os.mkdir(os.path.join(self.base, "empty"))
+        Path(self.base, "empty", "Thumbs.db").write_bytes(b"")
+        self.assertIsNone(self.problem(os.path.join(self.base, "empty")))
+
+    def test_codes(self):
+        cases = {
+            "relative": "location-not-absolute",
+            os.path.join(self.source, "thumbs"): "location-served",
+            os.path.join(self.node, "thumbs"): "location-node-folder",
+            self.base: "location-contains-source",
+            os.path.join(self.base, "no", "parent"): "location-parent-missing",
+        }
+        for path, code in cases.items():
+            with self.subTest(path=path):
+                self.assertEqual(self.problem(path), code)
+
+    def test_the_default_may_sit_in_the_node_folder_and_make_its_parents(self):
+        self.assertIsNone(self.problem(self.context.default_path))
+
+    def test_the_folder_in_use_is_the_same(self):
+        folder = os.path.join(self.base, "thumbs")
+        os.mkdir(folder)
+        self.assertEqual(self.problem(folder, current_path=folder), "location-same")
+
+    def test_a_folder_with_other_files_is_not_empty_unless_it_is_ours(self):
+        folder = os.path.join(self.base, "full")
+        os.mkdir(folder)
+        Path(folder, "photo.jpg").write_bytes(b"x")
+        self.assertEqual(self.problem(folder), "location-not-empty")
+        pl.init_folder(folder)
+        self.assertIsNone(self.problem(folder))
+
+    @unittest.skipIf(os.name == "nt" or os.geteuid() == 0, "needs POSIX modes")
+    def test_a_folder_that_refuses_writes(self):
+        folder = os.path.join(self.base, "ro")
+        os.mkdir(folder)
+        os.chmod(folder, 0o500)
+        self.addCleanup(os.chmod, folder, 0o700)
+        self.assertEqual(self.problem(folder), "location-not-writable")
+
+    def test_a_stat_that_does_not_answer_is_unavailable(self):
+        release = threading.Event()
+        self.addCleanup(release.set)
+
+        def stuck(*_args):
+            release.wait(10)
+
+        with patch.object(pl, "_filesystem_problem", stuck):
+            code = pl.location_problem(
+                os.path.join(self.base, "thumbs"),
+                purpose="move",
+                context=self.context,
+                timeout=0.1,
+            )
+        self.assertEqual(code, "location-unavailable")
+
+    def test_a_long_windows_path(self):
+        path = os.path.join(self.base, "t" * 220)
+        self.assertEqual(self.problem(path, long_paths=False), "location-path-too-long")
+
+    def test_every_code_has_a_message_without_a_path(self):
+        for code, (status, text) in pl.MESSAGES.items():
+            with self.subTest(code=code):
+                self.assertIn(status, (400, 409))
+                self.assertTrue(text.endswith("."))
+
+
+class TestNoLegacySaveCallers(unittest.TestCase):
+    def test_save_to_file_has_no_callers(self):
+        offenders = []
+        for folder in ("py", "utils", "database"):
+            for path in (REPO / folder).rglob("*.py"):
+                for number, line in enumerate(
+                    path.read_text(encoding="utf-8").splitlines(), 1
+                ):
+                    code = line.split("#", 1)[0]
+                    if (
+                        re.search(r"\bsave_to_file\(", code)
+                        and "def save_to_file" not in code
+                    ):
+                        if "PromptManagerConfig.save_to_file('" in line:
+                            continue  # its own docstring example
+                        offenders.append(f"{path.relative_to(REPO)}:{number}")
+        self.assertEqual(offenders, [])
+
+
+try:
+    from tests.test_api_images import ImageAPITestCase
+except ImportError:  # discovered with tests/ as the top-level directory
+    from test_api_images import ImageAPITestCase
+
+
+class TestLocationRoutes(ImageAPITestCase):
+    async def asyncSetUp(self):
+        await super().asyncSetUp()
+        self.addCleanup(preview_store.configure, None)
+
+    def use_folder(self):
+        folder = self.comfy_dir / "thumbs"
+        folder.mkdir()
+        marker_id = pl.init_folder(str(folder), created_by_pm=True)
+        preview_store.configure(
+            {"mode": "folder", "path": str(folder), "id": marker_id}
+        )
+        return folder
+
+    async def test_settings_get_names_the_location_with_its_path(self):
+        folder = self.use_folder()
+        resp = await self.client.get("/prompt_manager/settings")
+        location = (await resp.json())["thumbnail_location"]
+        self.assertEqual(location["mode"], "folder")
+        self.assertEqual(location["path"], str(folder))
+        self.assertTrue(location["available"])
+        self.assertIsNone(location["problem"])
+        self.assertIn("default_path", location)
+
+    async def test_settings_post_never_changes_the_location(self):
+        resp = await self.client.post(
+            "/prompt_manager/settings",
+            json={"thumbnail_location": {"mode": "folder", "path": "/x"}},
+        )
+        self.assertEqual(resp.status, 409)
+        body = await resp.json()
+        self.assertEqual(body["code"], "location-needs-move")
+        self.assertNotIn("/x", body["error"])
+
+    async def test_status_has_the_location_but_no_path(self):
+        folder = self.use_folder()
+        resp = await self.client.get("/prompt_manager/images/thumbnails/status")
+        body = await resp.text()
+        self.assertNotIn(str(folder), body)
+        self.assertEqual(
+            json.loads(body)["location"],
+            {"mode": "folder", "available": True, "problem": None},
+        )
+
+    async def test_a_source_inside_or_around_the_folder_is_refused(self):
+        from py.api import sources
+
+        folder = self.use_folder()
+        inside = folder / "sub"
+        inside.mkdir()
+        with patch(
+            "py.config.GalleryConfig.gallery_root_problem",
+            classmethod(lambda cls, path: (None, "")),
+        ):
+            for path in (inside, folder, self.comfy_dir):
+                with self.subTest(path=path):
+                    code, reason = sources.source_problem(str(path))
+                    self.assertEqual(code, "holds-thumbnails")
+                    self.assertEqual(reason, pl.HOLDS_THUMBNAILS_REASON)
+            self.assertEqual(sources.source_problem(str(self.output_dir))[0], None)
+
+    async def test_a_library_move_into_the_folder_is_refused(self):
+        from py.api import library_location as routes
+
+        folder = self.use_folder()
+        self.assertTrue(routes._inside_thumbnail_folder(str(folder / "lib")))
+        self.assertFalse(routes._inside_thumbnail_folder(str(self.output_dir)))
+
+    def test_startup_makes_a_location_inside_a_source_invalid(self):
+        inside = self.output_dir / "thumbs"
+        inside.mkdir()
+        marker_id = pl.init_folder(str(inside))
+        from py.config import PromptManagerConfig
+
+        value = {"mode": "folder", "path": str(inside), "id": marker_id}
+        with patch.object(PromptManagerConfig, "THUMBNAIL_LOCATION", value):
+            location = self.api.start_preview_location()
+        self.assertEqual((location.available, location.problem), (False, "invalid"))
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_api_workspace_images.py

@@ -908,20 +908,20 @@ class TestWorkspaceImages(ImageAPITestCase):
 
     async def test_one_cards_parse_error_spares_the_page(self):
         prompt = self._save_prompt("a fox")
-        for name, mtime in (("bad.png", 200), ("ok.png", 100)):
+        # Cards are read on the image pool (#523), in no fixed order: the
+        # parser fails on bad.png's own record (seed 6), not on a call count.
+        for name, mtime, seed in (("bad.png", 200, 6), ("ok.png", 100, 5)):
             path = records_png(
-                self.output_dir / name, seeded_records("a fox", 5), mtime
+                self.output_dir / name, seeded_records("a fox", seed), mtime
             )
             self.api.db.link_image_to_prompt(prompt, str(path))
         real_parse = header_params_of_images()
 
         def parsing(info):
-            if parsing.calls == 0:
-                parsing.calls += 1
+            if '"seed": 6' in info["prompt"]:
                 raise RuntimeError("unexpected parser bug")
             return real_parse(info)
 
-        parsing.calls = 0
         with (
             patch("py.api.images.header_params", side_effect=parsing),
             self.assertLogs(self.api.logger, "WARNING") as logged,

tests/test_browser_fast_reset.py

@@ -11,7 +11,7 @@ import time
 import types
 import unittest
 from pathlib import Path
-from unittest import mock
+import unittest.mock as mock
 
 try:
     from tests.open_handles import assert_closed

tests/test_browser_malloc_tuning.py

@@ -6,7 +6,7 @@ Large frees then go back to the OS instead of fragmenting per-thread arenas.
 import ctypes
 import sys
 import unittest
-from unittest import mock
+import unittest.mock as mock
 
 from tests.browser import malloc_tuning
 

tests/test_browser_slow_reset_watch.py

@@ -46,7 +46,6 @@ class TestResetWatch(unittest.TestCase):
         self.assertFalse(is_reset_path("/__test__/reset/extra"))
 
     def test_a_stalled_reset_reports_state_and_stacks_while_it_waits(self):
-        stream = io.StringIO()
         reported = threading.Event()
 
         class Stream(io.StringIO):

tests/test_bulk_library_delete.py

@@ -385,8 +385,8 @@ class TestArchivedReaders(LibraryDeleteCase):
 
     def setUp(self):
         super().setUp()
-        self.kept, _kn, _kp = self.paired("Kept cat", "kept blur")
-        self.gone, _gn, _gp = self.paired("Gone cat", "gone blur")
+        self.kept, _, _ = self.paired("Kept cat", "kept blur")
+        self.gone, _, _ = self.paired("Gone cat", "gone blur")
         for pid, category, tag in ((self.kept, "keep", "k"), (self.gone, "gone", "g")):
             self.db.update_prompt_metadata(pid, category=category, tags=[tag])
         self.apply([self.gone])
@@ -642,7 +642,7 @@ class TestPairedDelete(LibraryDeleteCase):
         # The negatives stay, and the image file stays on disk.
         self.assertTrue((self.root / "owl.png").exists())
         texts = [row[0] for row in rows(self.db, "SELECT text FROM prompts")]
-        self.assertTrue({"dark", "fog", "Bystander"} <= set(texts))
+        self.assertLessEqual({"dark", "fog", "Bystander"}, set(texts))
 
     def test_a_negative_used_by_another_positive_is_archived_never_deleted(self):
         shared = save(self.db, "Shared")

tests/test_cached_runs.py

@@ -14,7 +14,7 @@ import threading
 import types
 import unittest
 from collections import namedtuple
-from unittest import mock
+import unittest.mock as mock
 
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 

tests/test_database_migrations.py

@@ -140,8 +140,10 @@ class TestIdempotentMigrations(MigrationTestCase):
     def test_stale_prompts_new_from_a_failed_rebuild_does_not_block_startup(self):
         self._legacy_db(
             [
-                "INSERT INTO prompts (text, hash, workflow_name)"
-                " VALUES ('a', 'h1', 'wf')",
+                (
+                    "INSERT INTO prompts (text, hash, workflow_name)"
+                    " VALUES ('a', 'h1', 'wf')"
+                ),
                 "CREATE TABLE prompts_new (id INTEGER PRIMARY KEY, junk TEXT)",
                 "INSERT INTO prompts_new (junk) VALUES ('leftover')",
             ]
@@ -157,10 +159,14 @@ class TestIdempotentMigrations(MigrationTestCase):
         # DROP TABLE prompts with foreign keys ON cascades into generated_images
         self._legacy_db(
             [
-                "INSERT INTO prompts (text, hash, workflow_name)"
-                " VALUES ('a', 'h1', 'wf')",
-                "INSERT INTO generated_images (prompt_id, image_path, filename)"
-                " VALUES (1, '/out/a.png', 'a.png')",
+                (
+                    "INSERT INTO prompts (text, hash, workflow_name)"
+                    " VALUES ('a', 'h1', 'wf')"
+                ),
+                (
+                    "INSERT INTO generated_images (prompt_id, image_path, filename)"
+                    " VALUES (1, '/out/a.png', 'a.png')"
+                ),
             ]
         )
 
@@ -172,11 +178,15 @@ class TestIdempotentMigrations(MigrationTestCase):
     def test_rebuild_keeps_library_state_rows(self):
         self._legacy_db(
             [
-                "INSERT INTO prompts (text, hash, workflow_name)"
-                " VALUES ('a', 'h1', 'wf')",
-                "CREATE TABLE prompt_library_state (prompt_id INTEGER PRIMARY KEY,"
-                " title TEXT, FOREIGN KEY(prompt_id) REFERENCES prompts(id)"
-                " ON DELETE CASCADE)",
+                (
+                    "INSERT INTO prompts (text, hash, workflow_name)"
+                    " VALUES ('a', 'h1', 'wf')"
+                ),
+                (
+                    "CREATE TABLE prompt_library_state (prompt_id INTEGER PRIMARY KEY,"
+                    " title TEXT, FOREIGN KEY(prompt_id) REFERENCES prompts(id)"
+                    " ON DELETE CASCADE)"
+                ),
                 "INSERT INTO prompt_library_state VALUES (1, 'kept')",
             ]
         )
@@ -232,43 +242,59 @@ class TestIdempotentMigrations(MigrationTestCase):
         byte_id = "6a1b2c3d-4e5f-4a6b-8c9d-0e1f2a3b4c5d"
         self._legacy_db(
             [
-                "INSERT INTO prompts (text, hash, workflow_name)"
-                " VALUES ('a', 'h1', 'wf')",
-                "CREATE TABLE tags (id INTEGER PRIMARY KEY AUTOINCREMENT,"
-                " name TEXT NOT NULL UNIQUE)",
+                (
+                    "INSERT INTO prompts (text, hash, workflow_name)"
+                    " VALUES ('a', 'h1', 'wf')"
+                ),
+                (
+                    "CREATE TABLE tags (id INTEGER PRIMARY KEY AUTOINCREMENT,"
+                    " name TEXT NOT NULL UNIQUE)"
+                ),
                 "INSERT INTO tags (id, name) VALUES (3, 'img-only')",
-                "CREATE TABLE media_annotation_metadata (singleton_id INTEGER"
-                " PRIMARY KEY CHECK(singleton_id=1), schema_version INTEGER NOT"
-                " NULL CHECK(schema_version=1), image_index_revision INTEGER NOT"
-                " NULL DEFAULT 0 CHECK(image_index_revision>=0))",
+                (
+                    "CREATE TABLE media_annotation_metadata (singleton_id INTEGER"
+                    " PRIMARY KEY CHECK(singleton_id=1), schema_version INTEGER NOT"
+                    " NULL CHECK(schema_version=1), image_index_revision INTEGER NOT"
+                    " NULL DEFAULT 0 CHECK(image_index_revision>=0))"
+                ),
                 "INSERT INTO media_annotation_metadata VALUES (1, 1, 4)",
-                "CREATE TABLE media_annotation_files (id TEXT PRIMARY KEY"
-                " CHECK(length(id)=36), locator TEXT NOT NULL UNIQUE,"
-                " created_at TEXT NOT NULL)",
+                (
+                    "CREATE TABLE media_annotation_files (id TEXT PRIMARY KEY"
+                    " CHECK(length(id)=36), locator TEXT NOT NULL UNIQUE,"
+                    " created_at TEXT NOT NULL)"
+                ),
                 f"INSERT INTO media_annotation_files VALUES ('{file_id}',"
                 " '/out/a.png', '2026-10-22T00:00:00.000000+00:00')",
-                "CREATE TABLE media_annotation_bytes (id TEXT PRIMARY KEY"
-                " CHECK(length(id)=36), file_id TEXT NOT NULL REFERENCES"
-                " media_annotation_files(id) ON DELETE CASCADE, sha256 TEXT NOT"
-                " NULL CHECK(length(sha256)=64 AND sha256 NOT GLOB"
-                " '*[^0-9a-f]*'), size INTEGER NOT NULL CHECK(size>=0), mtime_ns"
-                " INTEGER NOT NULL, verified_at TEXT NOT NULL, first_seen_at TEXT"
-                " NOT NULL, tag_revision INTEGER NOT NULL DEFAULT 0"
-                " CHECK(tag_revision>=0), UNIQUE(file_id, sha256))",
-                "CREATE INDEX idx_media_annotation_bytes_fingerprint ON"
-                " media_annotation_bytes(file_id, size, mtime_ns)",
+                (
+                    "CREATE TABLE media_annotation_bytes (id TEXT PRIMARY KEY"
+                    " CHECK(length(id)=36), file_id TEXT NOT NULL REFERENCES"
+                    " media_annotation_files(id) ON DELETE CASCADE, sha256 TEXT NOT"
+                    " NULL CHECK(length(sha256)=64 AND sha256 NOT GLOB"
+                    " '*[^0-9a-f]*'), size INTEGER NOT NULL CHECK(size>=0), mtime_ns"
+                    " INTEGER NOT NULL, verified_at TEXT NOT NULL, first_seen_at TEXT"
+                    " NOT NULL, tag_revision INTEGER NOT NULL DEFAULT 0"
+                    " CHECK(tag_revision>=0), UNIQUE(file_id, sha256))"
+                ),
+                (
+                    "CREATE INDEX idx_media_annotation_bytes_fingerprint ON"
+                    " media_annotation_bytes(file_id, size, mtime_ns)"
+                ),
                 f"INSERT INTO media_annotation_bytes VALUES ('{byte_id}',"
                 f" '{file_id}', '{'a' * 64}', 3, 1700000000000000000,"
                 " '2026-10-22T00:00:00.000000+00:00',"
                 " '2026-10-22T00:00:00.000000+00:00', 2)",
-                "CREATE TABLE media_image_tags (byte_id TEXT NOT NULL REFERENCES"
-                " media_annotation_bytes(id) ON DELETE CASCADE, tag_id INTEGER"
-                " NOT NULL REFERENCES tags(id) ON DELETE CASCADE, position"
-                " INTEGER NOT NULL CHECK(position>=0), PRIMARY KEY(byte_id,"
-                " tag_id))",
+                (
+                    "CREATE TABLE media_image_tags (byte_id TEXT NOT NULL REFERENCES"
+                    " media_annotation_bytes(id) ON DELETE CASCADE, tag_id INTEGER"
+                    " NOT NULL REFERENCES tags(id) ON DELETE CASCADE, position"
+                    " INTEGER NOT NULL CHECK(position>=0), PRIMARY KEY(byte_id,"
+                    " tag_id))"
+                ),
                 "CREATE INDEX idx_media_image_tags_tag ON media_image_tags(tag_id)",
-                "CREATE UNIQUE INDEX idx_media_image_tags_position ON"
-                " media_image_tags(byte_id, position)",
+                (
+                    "CREATE UNIQUE INDEX idx_media_image_tags_position ON"
+                    " media_image_tags(byte_id, position)"
+                ),
                 f"INSERT INTO media_image_tags VALUES ('{byte_id}', 3, 0)",
             ]
         )
@@ -367,18 +393,28 @@ class TestIdempotentMigrations(MigrationTestCase):
     def test_image_table_is_rebuilt_with_uniqueness_by_full_path(self):
         self._legacy_db(
             [
-                "INSERT INTO prompts (text, hash, workflow_name)"
-                " VALUES ('a', 'h1', 'wf')",
+                (
+                    "INSERT INTO prompts (text, hash, workflow_name)"
+                    " VALUES ('a', 'h1', 'wf')"
+                ),
                 # same basename in two folders: both must survive
-                "INSERT INTO generated_images (prompt_id, image_path, filename)"
-                " VALUES (1, '/out/2026-01-01/a.png', 'a.png')",
-                "INSERT INTO generated_images (prompt_id, image_path, filename)"
-                " VALUES (1, '/out/2026-01-02/a.png', 'a.png')",
+                (
+                    "INSERT INTO generated_images (prompt_id, image_path, filename)"
+                    " VALUES (1, '/out/2026-01-01/a.png', 'a.png')"
+                ),
+                (
+                    "INSERT INTO generated_images (prompt_id, image_path, filename)"
+                    " VALUES (1, '/out/2026-01-02/a.png', 'a.png')"
+                ),
                 # two spellings of one file: only the newest row survives
-                "INSERT INTO generated_images (prompt_id, image_path, filename)"
-                " VALUES (1, '/out/x/../b.png', 'b.png')",
-                "INSERT INTO generated_images (prompt_id, image_path, filename)"
-                " VALUES (1, '/out/b.png', 'b.png')",
+                (
+                    "INSERT INTO generated_images (prompt_id, image_path, filename)"
+                    " VALUES (1, '/out/x/../b.png', 'b.png')"
+                ),
+                (
+                    "INSERT INTO generated_images (prompt_id, image_path, filename)"
+                    " VALUES (1, '/out/b.png', 'b.png')"
+                ),
             ]
         )
 

tests/test_diagnostics_config.py

@@ -182,7 +182,7 @@ class TestAdminEndpointsUseConfigPath(unittest.TestCase):
                 self.assertIsNone(warning)
                 self.assertEqual(os.path.dirname(snapshot), folder)
                 with open(snapshot, "rb") as handle:
-                    self.assertTrue(handle.read(16) == b"SQLite format 3\x00")
+                    self.assertEqual(handle.read(16), b"SQLite format 3\x00")
             finally:
                 os.unlink(snapshot)
         finally:

tests/test_execution_history_events.py

@@ -31,6 +31,20 @@ def message(kind, job_id=JOB, **fields):
     return (kind, {"prompt_id": job_id, **fields})
 
 
+def hash_recording_kind():
+    """A str subclass for event kinds, and the list of hashes taken of it."""
+    hashed = []
+
+    class OversizedKind(str):
+        __eq__ = str.__eq__
+
+        def __hash__(self):
+            hashed.append(len(self))
+            return str.__hash__(self)
+
+    return OversizedKind, hashed
+
+
 def finish(messages, completed=True):
     return make_finish(SESSION, 0, EPOCH, Status("success", completed, messages), 500)
 
@@ -346,13 +360,10 @@ class ExecutionHistoryEventsTests(unittest.TestCase):
         self.assertLessEqual(len(encode_command(command)), 2048)
 
     def test_oversized_unknown_kind_is_ignored_without_hashing(self):
-        class OversizedKind(str):
-            def __hash__(self):
-                raise AssertionError("Oversized event kind must not be hashed")
-
+        kind_class, hashed = hash_recording_kind()
         command = finish(
             [
-                message(OversizedKind("x" * 1_000_000)),
+                message(kind_class("x" * 1_000_000)),
                 message("execution_success", timestamp=300),
             ]
         )
@@ -361,19 +372,16 @@ class ExecutionHistoryEventsTests(unittest.TestCase):
             (result.outcome, result.reason), ("succeeded", "terminal_success")
         )
         self.assertLessEqual(len(encode_command(command)), 2048)
+        self.assertEqual(hashed, [], "Oversized event kind must not be hashed")
 
     def test_encoder_rejects_oversized_kind_without_hashing(self):
-        class OversizedKind(str):
-            def __hash__(self):
-                raise AssertionError("Oversized event kind must not be hashed")
-
+        kind_class, hashed = hash_recording_kind()
         command = finish([message("execution_success")])
-        event = LifecycleEvent(
-            OversizedKind("x" * 1_000_000), JOB, None, None, None, None
-        )
+        event = LifecycleEvent(kind_class("x" * 1_000_000), JOB, None, None, None, None)
         with self.assertRaises(ValueError):
             encode_command(
                 replace(
                     command, evidence=TerminalEvidence((event,), False, False, False)
                 )
             )
+        self.assertEqual(hashed, [], "Oversized event kind must not be hashed")

tests/test_execution_output_capture.py

@@ -17,7 +17,7 @@ class Hostile:
         raise AssertionError("host scalar coercion")
 
     def __bool__(self):
-        raise AssertionError("host truth test")
+        raise TypeError("host truth test")
 
     def __eq__(self, other):
         raise AssertionError("host equality")

tests/test_exit_cancel.py

@@ -24,7 +24,7 @@ import tempfile
 import textwrap
 import threading
 import unittest
-from unittest import mock
+import unittest.mock as mock
 
 ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 sys.path.insert(0, ROOT)

tests/test_exit_window_threads.py

@@ -26,7 +26,7 @@ import types
 import unittest
 from concurrent.futures import ThreadPoolExecutor
 from pathlib import Path
-from unittest import mock
+import unittest.mock as mock
 
 from py.api import thumbnail_auto
 from utils import image_monitor, parallel
@@ -146,6 +146,18 @@ class TestPreviewQueueRefusedAtShutdown(unittest.TestCase):
 
 
 class TestMapParallelRefusedAtShutdown(unittest.TestCase):
+    def setUp(self):
+        # The job pool is long-lived (#523): start each test without one, so
+        # the patched pool class is the one created.
+        self.assertTrue(parallel.shutdown_job_pool(30))
+        self.addCleanup(parallel.shutdown_job_pool, 30)
+
+    def test_the_refused_pool_is_not_reused(self):
+        with mock.patch.object(parallel, "ThreadPoolExecutor", _ShutPool):
+            parallel.map_parallel(lambda n: n, [1, 2], 2)
+        self.assertFalse(parallel.job_pool_started())
+        self.assertEqual(parallel.map_parallel(lambda n: n + 1, [1, 2], 2), [2, 3])
+
     def test_a_shut_pool_runs_the_items_on_the_calling_thread(self):
         records = _capture(self, "prompt_manager.parallel")
         with mock.patch.object(parallel, "ThreadPoolExecutor", _ShutPool):

tests/test_file_prompt.py

@@ -7,7 +7,7 @@ I/O: history comes in through ``lookup``.
 
 import json
 import unittest
-from unittest import mock
+import unittest.mock as mock
 
 from database.run_attribution import RecordedOutput
 from tests.test_pair_scan import flux_graph, sampled_graph
@@ -564,6 +564,66 @@ class TestUndecidedGraph(unittest.TestCase):
         self.assertEqual(decision.review, "untraced")
 
 
+def _search_list(text="fox", side="positive"):
+    """f22: a PromptSearchList batch (no PromptManager node) feeds CLIPTextEncode."""
+    graph = parity.build("f22")["prompt"]
+    graph["10"]["inputs"]["text"] = text
+    if side == "negative":
+        # The search feeds the negative; the positive is typed text.
+        graph["6"]["inputs"]["text"] = parity.POS
+        graph["7"]["inputs"]["text"] = ["10", 0]
+    return graph
+
+
+class TestSearchTextIsNeverAPrompt(unittest.TestCase):
+    """#548: the PromptSearchList query is a search, never the prompt."""
+
+    def test_the_search_text_is_never_linked_or_stored(self):
+        for policy in Policy:
+            with self.subTest(policy=policy):
+                decision = _decide(
+                    _graph(_search_list()), policy=policy, lookup=_Lookup()
+                )
+                self.assertEqual(decision.kind, "never")
+                self.assertIsNone(decision.text)
+                self.assertEqual(decision.unlinked_status, "unresolved")
+                self.assertTrue(decision.try_recorded_run)
+
+    def test_a_search_text_from_a_primitive_is_never_linked(self):
+        graph = _search_list()
+        graph["10"]["inputs"]["text"] = ["30", 0]
+        graph["30"] = {"class_type": "PrimitiveString", "inputs": {"value": "fox"}}
+        for policy in Policy:
+            with self.subTest(policy=policy):
+                decision = _decide(_graph(graph), policy=policy, lookup=_Lookup())
+                self.assertEqual(decision.kind, "never")
+                self.assertIsNone(decision.text)
+
+    def test_an_empty_search_text_is_unchanged(self):
+        """Regression guard (passes on the base): nothing to exclude."""
+        for policy in Policy:
+            with self.subTest(policy=policy):
+                decision = _decide(
+                    _graph(_search_list("")), policy=policy, lookup=_Lookup()
+                )
+                self.assertEqual((decision.kind, decision.text), ("never", None))
+
+    def test_without_a_sampler_any_search_list_query_is_excluded(self):
+        graph = _search_list()
+        del graph["3"]
+        self.assertTrue(file_prompt._search_text(graph, " fox "))
+        self.assertFalse(file_prompt._search_text(graph, "a fox"))
+        self.assertFalse(file_prompt._search_text(None, "fox"))
+
+    def test_a_search_on_the_negative_keeps_the_typed_positive(self):
+        """Regression guard (passes on the base): only the positive's source
+        is excluded, so the legacy answer from typed text still links."""
+        graph = _search_list(side="negative")
+        decision = _decide(_graph(graph), lookup=_Lookup())
+        self.assertEqual((decision.kind, decision.text), ("positive", parity.POS))
+        self.assertEqual(decision.source, "legacy-parser")
+
+
 class TestStepsWithoutAnUndecidedGraph(unittest.TestCase):
     def test_step_9_ambiguous_parameters_only(self):
         meta = {

tests/test_focused_node.py

@@ -2,7 +2,7 @@
 
 import logging
 import unittest
-from unittest import mock
+import unittest.mock as mock
 
 from prompt_manager import PromptManager, PromptManagerFocused
 from utils.prompt_graph import positive_prompt_nodes, run_prompt_nodes

tests/test_gallery_listing.py

@@ -312,7 +312,7 @@ class RootContainsTests(unittest.TestCase):
         root = os.path.normcase(os.path.realpath(tempfile.gettempdir()))
         inside = os.path.join(root, "x.png")
         self.assertTrue(root_contains(root, inside))
-        self.assertTrue(root_contains(root, inside.upper()) == (os.name == "nt"))
+        self.assertEqual(root_contains(root, inside.upper()), os.name == "nt")
 
 
 if __name__ == "__main__":

tests/test_image_monitor_singleton.py

@@ -392,7 +392,10 @@ class TestStartStop(unittest.TestCase):
             self.assertLogs("prompt_manager.image_monitor", "WARNING") as logs,
         ):
             self.assertFalse(self.monitor.stop_monitoring(timeout=5.0))
-        self.assertEqual(fake.calls[-1], ("join", 0.0))
+        # The stop runs on its own thread and gets 0 s too: it may not have
+        # returned yet, and then nothing is joined at all.
+        joins = [call for call in fake.calls if call[0] == "join"]
+        self.assertTrue(all(call == ("join", 0.0) for call in joins), fake.calls)
         self.assertIn(
             "watchdog observer still running after 0.0 s", "\n".join(logs.output)
         )
@@ -401,6 +404,80 @@ class TestStartStop(unittest.TestCase):
     def test_stop_monitoring_without_an_observer_returns_true(self):
         self.assertTrue(self.monitor.stop_monitoring())
 
+    def test_threads_the_observer_starts_are_daemons(self):
+        # watchdog 7 on Windows starts a plain threading.Thread per watch in
+        # observer.start(); a non-daemon one holds the interpreter's exit
+        # before any atexit callback runs (#561).
+        fake = ReaderObserver()
+        self.addCleanup(fake.release.set)
+        self._start_with(fake)
+        self.assertIsNotNone(fake.reader)
+        self.assertTrue(fake.reader.daemon)
+        self.assertFalse(threading.current_thread().daemon)
+
+    def test_an_observer_that_fails_to_start_on_its_thread_is_reported(self):
+        fake = FakeObserver()
+        fake.start = MagicMock(side_effect=OSError("handle refused"))
+        with self.assertLogs("prompt_manager.image_monitor", "ERROR") as logs:
+            with patch.object(im_mod, "Observer", return_value=fake):
+                self.monitor.start_monitoring([self.tmp.name])
+        self.assertIn("handle refused", "\n".join(logs.output))
+        self.assertFalse(self.monitor.is_monitoring)
+
+    def test_an_observer_stop_that_never_returns_is_bounded(self):
+        # watchdog's observer.stop() joins its emitters (and, in 7.x on
+        # Windows, their reader threads) without a limit (#561).
+        fake = StuckStopObserver()
+        self.addCleanup(fake.release.set)
+        self._start_with(fake)
+        with self.assertLogs("prompt_manager.image_monitor", "WARNING") as logs:
+            self.assertFalse(self.monitor.stop_monitoring(timeout=0.05))
+        self.assertIn("watchdog observer still running", "\n".join(logs.output))
+        self.assertTrue(fake.entered.wait(30))
+        self.assertFalse(self.monitor.is_monitoring)
+        # A second stop waits for the stop already running; it never calls
+        # observer.stop() a second time.
+        fake.release.set()
+        self.assertTrue(self.monitor.stop_monitoring())
+        self.assertEqual(fake.stop_calls, 1)
+        self.assertFalse(self.monitor._unfinished)
+
+
+class ReaderObserver(FakeObserver):
+    """A FakeObserver whose start() starts a plain thread, as watchdog 7's
+    Windows emitter does for its ReadDirectoryChangesW reader."""
+
+    def __init__(self):
+        super().__init__()
+        self.release = threading.Event()
+        self.reader = None
+
+    def start(self):
+        self.reader = threading.Thread(target=self.release.wait)
+        self.reader.start()
+        super().start()
+
+    def stop(self):
+        self.release.set()
+        self.reader.join(30)
+        super().stop()
+
+
+class StuckStopObserver(FakeObserver):
+    """A FakeObserver whose stop() does not return until ``release``."""
+
+    def __init__(self):
+        super().__init__()
+        self.entered = threading.Event()
+        self.release = threading.Event()
+        self.stop_calls = 0
+
+    def stop(self):
+        self.stop_calls += 1
+        self.entered.set()
+        self.release.wait(30)
+        super().stop()
+
 
 class FakeEvent:
     def __init__(self, path, is_directory=False):

tests/test_image_pools.py

@@ -0,0 +1,241 @@
+"""Image work runs on PromptManager's own pools, never the default executor (#523).
+
+glibc keeps each thread's malloc arena at its high-water mark, so image work
+spread over the default executor's threads (min(32, cpus + 4)) kept an
+image-sized buffer per thread. Interactive image work (card facts, inspector
+reads, view previews) runs on the fixed interactive image pool
+(``pm-image``); jobs (scan metadata, thumbnail jobs, capture previews) on the
+long-lived Worker threads pool (``pm-worker``). After a scan or thumbnail
+job, glibc's free pages are released once (``malloc_trim``).
+"""
+
+import asyncio
+import threading
+from unittest.mock import patch
+
+import py.api as api_package
+import py.api.images as images_module
+import py.api.inspection_service as inspection_service
+import py.api.thumbnail_auto as auto
+from utils import parallel
+
+try:
+    from tests.test_api_images import make_png
+    from tests.test_thumbnail_auto import WAIT, AutoThumbnailCase, _entry
+except ImportError:  # discovered with tests/ as the top-level directory
+    from test_api_images import make_png
+    from test_thumbnail_auto import WAIT, AutoThumbnailCase, _entry
+
+IMAGE_THREAD = auto.POOL_PREFIX + "_"
+JOB_THREAD = parallel.JOB_THREAD_PREFIX + "_"
+
+
+class ImagePoolCase(AutoThumbnailCase):
+    async def asyncSetUp(self):
+        await super().asyncSetUp()
+        self.assertTrue(parallel.shutdown_job_pool(WAIT))
+        self.addCleanup(parallel.shutdown_job_pool, WAIT)
+        self.threads = []
+        self.lock = threading.Lock()
+
+    def spy(self, owner, name):
+        """Record the thread every call of ``owner.name`` runs on."""
+        original = getattr(owner, name)
+
+        def recording(*args, **kwargs):
+            with self.lock:
+                self.threads.append(threading.current_thread().name)
+            return original(*args, **kwargs)
+
+        patcher = patch.object(owner, name, recording)
+        patcher.start()
+        self.addCleanup(patcher.stop)
+
+    def assert_threads(self, prefix):
+        self.assertTrue(self.threads, "the spied call never ran")
+        self.assertTrue(
+            all(name.startswith(prefix) for name in self.threads), self.threads
+        )
+
+    async def run_job(self, path, body=None):
+        response = await self.client.post(path, json=body or {})
+        self.assertEqual(response.status, 202, await response.text())
+        job = self.api._jobs.get((await response.json())["job"]["id"])
+        await asyncio.wait_for(asyncio.shield(job.task), WAIT)
+        return job
+
+
+class TestInteractiveImagePool(ImagePoolCase):
+    async def test_workspace_card_facts_are_read_on_the_image_pool(self):
+        for index in range(5):
+            make_png(self.output_dir / f"c{index}.png", size=(32, 32))
+        self.spy(images_module, "_card_header")
+        response = await self.client.get(
+            "/prompt_manager/images/output?mode=workspace&limit=100"
+        )
+        self.assertEqual(response.status, 200, await response.text())
+        images = (await response.json())["images"]
+        self.assertEqual([image["width"] for image in images], [32] * 5)
+        self.assert_threads(IMAGE_THREAD)
+        self.assertEqual(len(self.threads), 5)
+
+    async def test_cached_card_facts_need_no_image_pool_trip(self):
+        make_png(self.output_dir / "c.png", size=(32, 32))
+        url = "/prompt_manager/images/output?mode=workspace&limit=100"
+        await (await self.client.get(url)).read()
+        self.spy(images_module, "_card_header")
+        response = await self.client.get(url)
+        self.assertEqual((await response.json())["images"][0]["width"], 32)
+        self.assertEqual(self.threads, [])
+
+    async def test_the_inspector_reads_on_the_image_pool(self):
+        make_png(self.output_dir / "i.png", size=(32, 32))
+        self.spy(inspection_service, "read_inspection_file")
+        response = await self.client.get("/prompt_manager/images/inspect/i.png?root=0")
+        self.assertEqual(response.status, 200, await response.text())
+        self.assert_threads(IMAGE_THREAD)
+
+    async def test_view_previews_and_card_reads_share_three_threads(self):
+        names = [f"v{i}.png" for i in range(auto.ON_DEMAND_LIMIT + 3)]
+        for name in names:
+            make_png(self.output_dir / name, size=(64, 64))
+        calls = []
+        original = self.api._generate_one
+
+        def recording(*args, **kwargs):
+            calls.append(threading.current_thread().name)
+            return original(*args, **kwargs)
+
+        self.api._generate_one = recording
+        for name in names:
+            url = _entry(self.api, self.output_dir, name)["thumbnail_url"]
+            await (await self.client.get(url)).read()
+        self.assertEqual(len(calls), len(names))
+        self.assertTrue(all(name.startswith(IMAGE_THREAD) for name in calls), calls)
+        self.assertLessEqual(len(self.api._image_pool_threads()), auto.IMAGE_POOL_SIZE)
+
+    def test_map_image_keeps_order_and_runs_inline_on_a_pool_thread(self):
+        self.assertEqual(self.api._map_image(lambda n: n * 2, [3, 1, 2]), [6, 2, 4])
+        nested = self.api._image_pool().submit(
+            self.api._map_image, lambda _: threading.current_thread().name, [1]
+        )
+        (name,) = nested.result(WAIT)
+        self.assertTrue(name.startswith(IMAGE_THREAD), name)
+
+    def test_map_image_after_a_close_runs_on_the_calling_thread(self):
+        pool = self.api._image_pool()
+        pool.shutdown(wait=True)
+        here = threading.current_thread().name
+        with patch.object(self.api, "_image_pool", return_value=pool):
+            names = self.api._map_image(
+                lambda _: threading.current_thread().name, [1, 2]
+            )
+        self.assertEqual(names, [here, here])
+
+    async def test_after_the_final_close_no_image_thread_starts(self):
+        await asyncio.get_running_loop().run_in_executor(
+            None, lambda: self.api.close_auto_thumbnails(final=True)
+        )
+        self.assertIsNone(self.api._image_pool())
+        here = threading.current_thread().name
+        names = self.api._map_image(lambda _: threading.current_thread().name, [1])
+        self.assertEqual(names, [here])
+        name = await self.api._run_image(lambda: threading.current_thread().name)
+        self.assertFalse(name.startswith(IMAGE_THREAD), name)
+        self.assertEqual(self.api._image_pool_threads(), [])
+
+    def test_map_image_runs_items_a_shutdown_cancelled_here(self):
+        entered = threading.Barrier(auto.IMAGE_POOL_SIZE + 1)
+        release = threading.Event()
+        self.addCleanup(release.set)
+        pool = self.api._image_pool()
+        for _ in range(auto.IMAGE_POOL_SIZE):  # occupy every pool thread
+            pool.submit(lambda: (entered.wait(WAIT), release.wait(WAIT)))
+        entered.wait(WAIT)
+        here = threading.current_thread().name
+        results, submitted = {}, threading.Event()
+
+        class Counting:
+            calls = 0
+
+            def submit(self, *args):
+                future = pool.submit(*args)
+                Counting.calls += 1
+                if Counting.calls == 2:
+                    submitted.set()
+                return future
+
+        def call():
+            with patch.object(self.api, "_image_pool", return_value=Counting()):
+                results["names"] = self.api._map_image(
+                    lambda _: threading.current_thread().name, [1, 2]
+                )
+
+        caller = threading.Thread(target=call, name="map-image-caller")
+        caller.start()
+        # The caller's two items are queued behind the busy threads; the
+        # shutdown cancels them and the caller runs them itself.
+        self.assertTrue(submitted.wait(WAIT))
+        pool.shutdown(wait=False, cancel_futures=True)
+        caller.join(WAIT)
+        release.set()
+        self.assertFalse(caller.is_alive())
+        self.assertEqual(results["names"], ["map-image-caller"] * 2)
+        self.assertNotEqual(here, "map-image-caller")
+
+    async def test_run_image_after_a_close_uses_the_default_executor(self):
+        pool = self.api._image_pool()
+        pool.shutdown(wait=True)
+        with patch.object(self.api, "_image_pool", return_value=pool):
+            name = await self.api._run_image(lambda: threading.current_thread().name)
+        self.assertFalse(name.startswith(IMAGE_THREAD), name)
+
+
+class TestJobPool(ImagePoolCase):
+    def test_scan_metadata_is_read_on_the_job_pool(self):
+        paths = [
+            make_png(self.output_dir / f"s{i}.png", size=(16, 16)) for i in range(4)
+        ]
+        self.spy(self.api, "_extract_comfyui_metadata")
+        results = self.api._extract_batch_metadata_sync(paths)
+        self.assertEqual([path for path, _ in results], paths)
+        self.assert_threads(JOB_THREAD)
+
+    async def test_thumbnail_job_writes_on_the_job_pool_and_trims_after(self):
+        for index in range(3):
+            make_png(self.output_dir / f"t{index}.png", size=(64, 64))
+        self.spy(self.api, "_generate_one")
+        with patch.object(api_package, "release_free_memory") as trim:
+            job = await self.run_job("/prompt_manager/jobs/thumbnails")
+        self.assertEqual(job.state, "finished")
+        self.assert_threads(JOB_THREAD)
+        trim.assert_called_once_with()
+
+    async def test_scan_job_trims_after_it_finishes(self):
+        make_png(self.output_dir / "s.png", size=(16, 16))
+        states = []
+
+        def trim():
+            states.append(self.api._jobs.active("scan"))
+            return True
+
+        with patch.object(api_package, "release_free_memory", side_effect=trim):
+            job = await self.run_job("/prompt_manager/jobs/scan")
+        self.assertEqual(job.state, "finished")
+        self.assertGreaterEqual(len(states), 1)
+        self.assertIsNone(states[0], "trimmed after the scan finished")
+
+    async def test_a_failing_trim_never_fails_the_job(self):
+        make_png(self.output_dir / "t.png", size=(64, 64))
+        with patch.object(
+            api_package, "release_free_memory", side_effect=RuntimeError("no")
+        ):
+            job = await self.run_job("/prompt_manager/jobs/thumbnails")
+        self.assertEqual(job.state, "finished")
+
+    async def test_capture_previews_write_on_the_job_pool(self):
+        path = make_png(self.output_dir / "a.png", size=(64, 64))
+        self.spy(self.api, "_generate_one")
+        self.assertEqual(self.api.queue_capture_thumbnail(str(path)), "queued")
+        await self._idle()
+        self.assert_threads(JOB_THREAD)

tests/test_init_package.py

@@ -136,6 +136,11 @@ def cleanup_package(package, require_stopped=True):
     if registration is not None:
         assert registration.dispose(3), "package history worker leaked"
     close_every_database()
+    # The package's exit actions outlive it otherwise: at interpreter exit
+    # they would import from a package no longer in sys.modules (#580).
+    exit_signal = getattr(package, "_exit_signal", None)
+    if exit_signal is not None:
+        exit_signal.reset()
     sys.modules.pop(package.__name__, None)
 
 
@@ -390,7 +395,39 @@ class TestConsoleBanner(unittest.TestCase):
 
         stream.flush()
         banner = stream.buffer.getvalue().decode("cp1252")
-        self.assertIn("Loaded:", banner)
+        lines = [
+            line
+            for line in banner.splitlines()
+            if "PromptManager" in line or "loaded" in line
+        ]
+        self.assertEqual(len(lines), 1, banner)
+        self.assertRegex(
+            lines[0], r"\[ComfyUI-PromptManager\] Version:.* \S+ - \d+ tools loaded$"
+        )
+        self.assertNotIn("Loaded:", banner)
+
+
+class TestFixtureExitActions(unittest.TestCase):
+    """A disposed fixture package runs nothing at interpreter exit (#580)."""
+
+    def test_a_disposed_package_leaves_no_exit_action(self):
+        tmp = tempfile.TemporaryDirectory()
+        self.addCleanup(tmp.cleanup)
+        self.addCleanup(close_every_database)
+        output_dir = os.path.join(tmp.name, "output")
+        os.makedirs(output_dir)
+        name = "prompt_manager_pkg_exit_actions"
+        self.addCleanup(sys.modules.pop, name, None)
+
+        with contextlib.redirect_stdout(io.StringIO()):
+            with load_package(name, os.path.join(tmp.name, "p.db"), output_dir) as (
+                package,
+                _,
+            ):
+                signal = package._exit_signal
+                self.assertTrue(signal._on_exit, "the package installs exit actions")
+
+        self.assertEqual(signal._on_exit, [])
 
 
 class PriorFileHandler(logging.FileHandler):
@@ -527,7 +564,7 @@ class TestPackageLoggerIsolation(unittest.TestCase):
         def log_from_background_thread():
             try:
                 logging.getLogger("prompt_manager.late_emitter").warning(message)
-            except BaseException as error:
+            except Exception as error:
                 errors.append(error)
 
         self.handler.addFilter(pause_before_handler_lock)
@@ -553,7 +590,7 @@ class TestPackageLoggerIsolation(unittest.TestCase):
         original_print = print
 
         def fail_banner(*args, **kwargs):
-            if any("Total:" in str(arg) for arg in args):
+            if any("tools loaded" in str(arg) for arg in args):
                 captured["package"] = sys.modules[name]
                 captured["handlers"] = [
                     h
@@ -587,13 +624,16 @@ PACKAGE_THREAD_NAMES = ("PromptManagerPromptCleanup", "PromptManagerImageWorker"
 
 def package_threads():
     """Live threads this design owns: the tracker, the image worker, and the
-    watchdog observer and emitters (which have no name of their own)."""
+    watchdog observer and emitters (which have no name of their own).
+    watchdog 7's InotifyFD, one daemon reader per process that no observer
+    stop ends, is not the package's."""
     from watchdog.utils import BaseThread
 
     return {
         thread
         for thread in threading.enumerate()
-        if thread.name in PACKAGE_THREAD_NAMES or isinstance(thread, BaseThread)
+        if thread.name in PACKAGE_THREAD_NAMES
+        or (isinstance(thread, BaseThread) and type(thread).__name__ != "InotifyFD")
     }
 
 
@@ -759,6 +799,45 @@ class TestPackageTeardown(PackageTeardownCase):
         self.assertIsNone(seen["worker"])
         self.assertTrue(all(result.values()), result)
 
+    def test_teardown_stops_the_job_pool_once_a_job_used_it(self):
+        """#523: the long-lived job pool is a teardown part of its own."""
+        package = self.load()
+        parallel = sys.modules[package.__name__ + ".utils.parallel"]
+        self.assertEqual(parallel.map_parallel(lambda n: n * 2, [1, 2], 2), [2, 4])
+        # This package's own pool (the suite's top-level one may also run).
+        threads = list(parallel._pool[1]._threads)
+        self.assertTrue(threads)
+
+        result = package._stop_background_work()
+
+        self.assertEqual(list(result), ["monitor", "thumbnails", "workers", "tracker"])
+        self.assertTrue(all(result.values()), result)
+        self.assertFalse(parallel.job_pool_started())
+        self.assertFalse(any(t.is_alive() for t in threads))
+
+    def test_teardown_reports_a_job_thread_past_its_bound(self):
+        package = self.load(require_stopped=False)
+        parallel = sys.modules[package.__name__ + ".utils.parallel"]
+        entered, release = threading.Event(), threading.Event()
+
+        def hold(_):
+            entered.set()
+            release.wait(30)
+
+        caller = threading.Thread(target=parallel.map_parallel, args=(hold, [1], 1))
+        caller.start()
+        self.addCleanup(caller.join, 30)
+        self.addCleanup(release.set)
+        self.assertTrue(entered.wait(30))
+        with (
+            mock.patch.object(parallel, "JOB_POOL_JOIN_SECONDS", 0.05),
+            self.assertLogs("prompt_manager.init", "WARNING") as logs,
+        ):
+            result = package._stop_background_work()
+        self.assertFalse(result["workers"])
+        self.assertTrue(result["tracker"])
+        self.assertRegex("\n".join(logs.output), r"not stopped in time .*workers")
+
     def test_teardown_kills_ffmpeg_and_stops_the_preview_worker(self):
         package = self.load()
         held = self.hold_a_preview(package, advance=4.0, kill_releases=True)

tests/test_legacy_parity_gate.py

@@ -108,6 +108,15 @@ LEGACY_WRONG = {
         "a cozy library with tall shelves",
         "legacy shows branch 1; the file name names branch 4's saver",
     ),
+    # #548, the one shape where nothing is read on purpose: legacy shows a
+    # PromptSearchList's search text ("fox") as the positive, but that is the
+    # library query, not the prompt the batch ran. The scan and the monitor
+    # never store or link it either (utils.file_prompt._search_text).
+    ("inspection_parity", "f22"): (
+        None,
+        "legacy shows the PromptSearchList search text; each item is decided "
+        "at run time, so no positive is read (#548)",
+    ),
 }
 
 
@@ -149,6 +158,24 @@ class LegacyParityGateTest(unittest.TestCase):
                 self.assertEqual(text, expected)
                 self.assertNotEqual(text, legacy)
 
+    def test_the_search_list_query_is_never_stored_either(self):
+        """#548: the scan and the monitor depart from legacy for f22 too."""
+        from utils.file_prompt import Policy, decide_file_prompt
+
+        graph, workflow = corpora()["inspection_parity"]["f22"]
+        self.assertEqual(legacy_positive(graph, workflow), "fox")
+        for policy in Policy:
+            with self.subTest(policy=policy):
+                decision = decide_file_prompt(
+                    {"prompt": graph, "workflow": workflow},
+                    file_name="f22.png",
+                    file_size=None,
+                    in_output=True,
+                    lookup=lambda: None,
+                    policy=policy,
+                )
+                self.assertEqual((decision.kind, decision.text), ("never", None))
+
     def test_no_graph_leaves_the_legacy_agreement(self):
         recorded = json.loads(AGREEMENT_PATH.read_text(encoding="utf-8"))
         current = {name: agreeing(graphs) for name, graphs in corpora().items()}

tests/test_library.py

@@ -143,8 +143,6 @@ class TestLibrary(unittest.TestCase):
             self.db.get_library_positive(positive, variant_limit=201)
 
     def test_sorts_keysets_survive_anchor_deletion_and_insertions_without_writes(self):
-        import sqlite3
-
         a = self.save("Alpha", rating=2, tags=["tag"])
         b = self.save("beta", rating=5)
         c = self.save("charlie")

tests/test_library_delete_routes.py

@@ -297,7 +297,7 @@ class TestLibraryDeleteRoutes(LibraryDeleteRouteCase):
         )
         page = await response.json()
         self.assertEqual(page["archived_total"], 3)
-        self.assertTrue(set(item["id"] for item in page["items"]) <= set(kept))
+        self.assertLessEqual(set(item["id"] for item in page["items"]), set(kept))
         response = await self.client.request(
             "GET",
             "/prompt_manager/library?limit=2&shelf=archived"

tests/test_library_location_wiring.py

@@ -135,6 +135,7 @@ class TestLogsAndCache(_EnvCase):
 
             get_logger_manager()._setup_loggers()
         except Exception:
+            # best effort restore in teardown; must not hide the test result
             pass
 
     def test_lora_image_cache_follows_the_data_folder(self):

tests/test_library_move.py

@@ -18,7 +18,7 @@ import tempfile
 import threading
 import types
 import unittest
-from unittest import mock
+import unittest.mock as mock
 
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 

tests/test_library_move_review.py

@@ -22,7 +22,7 @@ import sqlite3
 import sys
 import threading
 import unittest
-from unittest import mock
+import unittest.mock as mock
 
 sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 

tests/test_local_inspect_parity.py

@@ -1112,10 +1112,10 @@ class LocalProjectionParityTests(unittest.TestCase):
                 self.assertEqual(_canonical_bytes(local), _canonical_bytes(server))
                 seen.update(server["record_formats"].values())
                 seen.add(server["workflow_graph"]["status"])
-        self.assertTrue(
-            {"reserialized-json", "original-text", "invalid", "limited"} <= seen
+        self.assertLessEqual(
+            {"reserialized-json", "original-text", "invalid", "limited"}, seen
         )
-        self.assertTrue({"parsed", "malformed", "limited"} <= seen)
+        self.assertLessEqual({"parsed", "malformed", "limited"}, seen)
 
 
 def _server_evidence(records, file_name=None):
@@ -1287,7 +1287,7 @@ class LocalResolverParityTests(unittest.TestCase):
     def test_local_roles_match_selection_record_sets(self):
         answers = self._compare(selection_cases.selection_cases())
         reasons = {answer["resolution"]["reason"] for answer in answers.values()}
-        self.assertTrue(
+        self.assertLessEqual(
             {
                 "Every sampler branch uses the same prompt pair",
                 "Multiple sampler branches",
@@ -1301,8 +1301,8 @@ class LocalResolverParityTests(unittest.TestCase):
                 "Negative prompt delimiter is absent",
                 "Parameters exceed the length limit",
                 "No A1111 parameters",
-            }
-            <= reasons
+            },
+            reasons,
         )
         # A stage reaching only previews is dropped: one sampler is named.
         self.assertEqual(
@@ -1352,7 +1352,7 @@ class LocalResolverParityTests(unittest.TestCase):
     def test_local_roles_match_golden_record_sets(self):
         answers = self._compare(resolver_cases.golden_cases())
         codes = {answer["resolution"]["reason_code"] for answer in answers.values()}
-        self.assertTrue(
+        self.assertLessEqual(
             {
                 "malformed",
                 "unsupported-node",
@@ -1364,16 +1364,16 @@ class LocalResolverParityTests(unittest.TestCase):
                 "graph-ceiling",
                 "no-sampler",
                 None,
-            }
-            <= codes
+            },
+            codes,
         )
         sources = {
             side["source"]
             for answer in answers.values()
             for side in answer["prompts"].values()
         }
-        self.assertTrue(
-            {"execution", "graph-inferred", "zeroed-conditioning"} <= sources
+        self.assertLessEqual(
+            {"execution", "graph-inferred", "zeroed-conditioning"}, sources
         )
 
     def test_committed_resolver_vectors_are_current(self):