feat(logs): review and apply rotated-log cleanup as a maintenance plan

POST /maintenance/preview {operation: "rotated_logs", options: {}} lists the
rotated copies Rule R allows, with size and time, and what it keeps (the
active log, links, other files); it writes nothing and answers the Plan
shape with basenames only, backup policy none and no disk key.

POST /maintenance/apply starts the "Rotated log copies" maintenance job
(admission read: runs beside a scan, refused beside another maintenance job
or an exclusive one). It deletes exactly the reviewed copies, or nothing and
fails plan-changed when any of them changed after the review; a copy that
cannot be deleted becomes an errors row. The token is consumed on the loop
turn the job starts. (#329)

py/api/__init__.py

@@ -5,6 +5,7 @@ Split into domain-specific mixins for maintainability:
 - ImageRoutesMixin: gallery, thumbnails, image serving and linking
 - AdminRoutesMixin: duplicates, stats, settings, diagnostics, maintenance, backup, scan
 - LoggingRoutesMixin: log management endpoints
+- LogCleanupMixin: the reviewed rotated-log cleanup (a maintenance plan)
 - AutotagRoutesMixin: auto-tagging model management and tagging
 - JobRoutesMixin: the session job registry behind Activity (py/api/jobs.py)
 - ImageTagJobsMixin: bulk Add tags / Auto-tag as image-tags jobs
@@ -65,6 +66,7 @@ from .duplicate_files import DuplicateFilesMixin
 from .maintenance_plans import PlanStore
 from .jobs import JobRegistry
 from .logging_routes import LoggingRoutesMixin
+from .log_cleanup import LogCleanupMixin
 from .autotag_routes import AutotagRoutesMixin
 from .lora_integration import LoraIntegrationMixin
 from .lora_import_routes import LoraImportRoutesMixin
@@ -323,6 +325,7 @@ class PromptManagerAPI(
     WorkflowStorageRoutesMixin,
     DuplicateFilesMixin,
     LoggingRoutesMixin,
+    LogCleanupMixin,
     AutotagRoutesMixin,
     LoraIntegrationMixin,
     LoraImportRoutesMixin,

py/api/log_cleanup.py

@@ -0,0 +1,203 @@
+"""Reviewed rotated-log cleanup as a maintenance plan (#329 System S12).
+
+``POST /prompt_manager/maintenance/preview {operation: "rotated_logs",
+options: {}}`` lists the rotated copies of the active log that Rule R allows
+(``utils/logging_config.py``: ``prompt_manager.log.<n>`` regular files that
+are not links, directly in the log folder) and writes nothing. The plan keeps
+each copy's name, size, ``mtime_ns`` and inode under its token; the response
+is the maintenance ``Plan`` shape with basenames only, a ``none`` backup
+policy (no library record changes) and no ``disk`` key.
+
+``POST /prompt_manager/maintenance/apply {token}`` starts a ``maintenance``
+job titled "Rotated log copies" with admission ``read``: it may run beside a
+scan and is refused only beside another maintenance job or an ``exclusive``
+one. The job deletes exactly the reviewed copies under the logger's files
+lock and the file handler's lock, or nothing, failing ``plan-changed``, when
+any of them is missing, is no longer a rotated copy or differs in size,
+``mtime_ns`` or inode. A copy that cannot be deleted (open in another program
+on Windows) is an ``errors`` row; the others are deleted.
+"""
+
+import datetime
+import json
+
+from aiohttp import web
+
+try:
+    from ...utils.logging_config import RotatedChanged, rotated_sort_key
+except ImportError:  # loaded as the top-level ``py`` package (tests)
+    from utils.logging_config import RotatedChanged, rotated_sort_key
+
+from .jobs import MAINTENANCE_JOB_KIND
+from .maintenance_plans import ScopeTooLarge
+
+ROTATED_LOGS = "rotated_logs"
+LOG_CLEANUP_TITLE = "Rotated log copies"
+LOGS_CHANGED = (
+    "The log files changed since the review; nothing was deleted. Review again."
+)
+LOG_CLEANUP_FAILED = "The log cleanup failed."
+TOO_MANY_LOG_FILES = "Too many log files to review at once."
+LOG_CLEANUP_MEDIA = (
+    "Deletes only the listed log files. No image, video or library record changes."
+)
+_GROUPS = ("changed", "protected", "errors")
+
+
+def size_label(size):
+    """``1000 bytes``, ``2.0 KB``, ``10.0 MB`` or ``1.2 GB`` (1 KB = 1024 bytes)."""
+    size = max(0, int(size or 0))
+    if size < 1024:
+        return f"{size} {'byte' if size == 1 else 'bytes'}"
+    for unit, scale in (("KB", 2**10), ("MB", 2**20)):
+        if size < scale * 1024:
+            return f"{size / scale:.1f} {unit}"
+    return f"{size / 2**30:.1f} GB"
+
+
+def time_label(mtime_ns):
+    """The local modification time as ``YYYY-MM-DD HH:MM``."""
+    return datetime.datetime.fromtimestamp(mtime_ns / 1e9).strftime("%Y-%m-%d %H:%M")
+
+
+def _count(count, singular, plural):
+    return f"{count} {singular if count == 1 else plural}"
+
+
+def _protected_reasons(rows):
+    """The plan's Protected reasons: what the cleanup keeps, zero counts left out."""
+    active = sum(1 for row in rows if row["kind"] == "active")
+    links = sum(1 for row in rows if row["kind"] == "link")
+    other = sum(1 for row in rows if row["kind"] == "other")
+    reasons = []
+    if active:
+        reasons.append("Kept: the active log")
+    if links:
+        reasons.append(f"Kept: {_count(links, 'link', 'links')}")
+    if other:
+        reasons.append(f"Kept: {_count(other, 'other file', 'other files')}")
+    return active + links + other, reasons
+
+
+def _scope_label(files):
+    if not files:
+        return "No rotated log copies"
+    total = sum(row["size"] for row in files)
+    return (
+        f"{_count(len(files), 'rotated log copy', 'rotated log copies')}"
+        f" · {size_label(total)}"
+    )
+
+
+class LogCleanupMixin:
+    """The ``rotated_logs`` maintenance plan and its job.
+
+    The logger manager is reached only through ``_get_logger_manager``
+    (``logging_routes.py``), so the tests can point it at a temporary folder.
+    """
+
+    async def preview_log_cleanup(self):
+        """The ``rotated_logs`` plan (runs inside the preview's lease)."""
+        from . import maintenance
+
+        manager = self._get_logger_manager()
+        try:
+            rows = await self._run_in_executor(manager.scan_log_folder)
+        except Exception:
+            self.logger.exception("Rotated log review failed")
+            return maintenance._failure("Failed to review maintenance", 500)
+        rotated = sorted(
+            (row for row in rows if row["kind"] == "rotated"),
+            key=rotated_sort_key,
+        )
+        files = [
+            {
+                "name": row["name"],
+                "size": row["size"],
+                "mtime_ns": row["mtime_ns"],
+                "ino": row["ino"],
+            }
+            for row in rotated
+        ]
+        protected, reasons = _protected_reasons(rows)
+        store = self._maintenance_plans
+        try:
+            token = store.issue(
+                ROTATED_LOGS,
+                json.dumps(files, sort_keys=True),
+                {"files": files, "protected": protected},
+                (),
+            )
+        except ScopeTooLarge:
+            return maintenance._failure(TOO_MANY_LOG_FILES, 413, "too-large")
+        plan = store.peek(token, ROTATED_LOGS)
+        return web.json_response(
+            {
+                "success": True,
+                "token": token,
+                "operation": ROTATED_LOGS,
+                "expires_at": maintenance._iso(plan.expires_at),
+                "scope": {"count": len(files), "label": _scope_label(files)},
+                "protected": {"count": protected, "reasons": reasons},
+                "backup": {
+                    "policy": "none",
+                    "destination_label": None,
+                    "expected_bytes": None,
+                },
+                "media": {"deletes_files": True, "label": LOG_CLEANUP_MEDIA},
+                "details": [
+                    {
+                        "label": row["name"],
+                        "detail": (
+                            f"{size_label(row['size'])} · {time_label(row['mtime_ns'])}"
+                        ),
+                    }
+                    for row in files
+                ],
+            },
+            headers={"Cache-Control": "no-store"},
+        )
+
+    def _start_log_cleanup(self, plan):
+        """Register the cleanup job (on the loop); raises JobBusy when refused."""
+        return self._jobs.start(
+            MAINTENANCE_JOB_KIND,
+            LOG_CLEANUP_TITLE,
+            admission="read",
+            cancellable=False,
+            scope={"operation": ROTATED_LOGS},
+            groups=_GROUPS,
+            runner=lambda job: self._run_log_cleanup(job, plan),
+        )
+
+    async def _run_log_cleanup(self, job, plan):
+        from . import maintenance
+
+        files = plan.payload["files"]
+        sizes = {row["name"]: row["size"] for row in files}
+        job.update(total=len(files), status_line="Deleting rotated log copies")
+        manager = self._get_logger_manager()
+        try:
+            result = await self._run_in_executor(manager.delete_rotated, files)
+        except RotatedChanged:
+            return maintenance._fail_job(job, "plan-changed", LOGS_CHANGED)
+        except Exception:
+            self.logger.exception("Rotated log cleanup failed")
+            return maintenance._fail_job(job, None, LOG_CLEANUP_FAILED)
+        for name in result["removed"]:
+            detail = f"Deleted · {size_label(sizes.get(name, 0))}"
+            job.record(
+                "changed", {"path": name, "detail": detail}, f"- {name} · {detail}"
+            )
+        for name, error in result["failed"]:
+            detail = self._public_error(error)
+            job.record(
+                "errors", {"path": name, "detail": detail}, f"! {name} · {detail}"
+            )
+        job.record_counted("protected", plan.payload["protected"])
+        removed, failed = len(result["removed"]), len(result["failed"])
+        line = f"Deleted {_count(removed, 'rotated log copy', 'rotated log copies')}"
+        if failed:
+            line += f", {failed} could not be deleted"
+        job.log_line(line)
+        job.update(processed=len(files), progress=100, status_line=line)

py/api/maintenance.py

@@ -2,7 +2,9 @@
 
 ``POST /prompt_manager/maintenance/preview {operation, options:{}}`` reviews
 one operation (``duplicate_prompts``, ``optimize``, ``unused_components`` or
-``missing_links``; ``database/maintenance.py``) off the event loop and
+``missing_links``; ``database/maintenance.py``; ``duplicate_files``,
+``py/api/duplicate_files.py``; ``rotated_logs``, the rotated log copies,
+``py/api/log_cleanup.py``, which has its own apply job) off the event loop and
 answers a ``Plan``: ``{success, token, operation, expires_at, scope:{count,
 label}, protected:{count, reasons}, backup:{policy, destination_label},
 media:{deletes_files, label}, details:[≤50 {label, detail}]}``. The preview
@@ -54,6 +56,7 @@ from aiohttp import web
 from .admin import _prune_safety_backups, _scan_location, _scan_roots
 from .job_routes import busy_response
 from .jobs import MAINTENANCE_JOB_KIND, JobBusy
+from .log_cleanup import ROTATED_LOGS
 from .maintenance_plans import PlanExpired, PlanUsed, ScopeTooLarge
 
 try:
@@ -83,7 +86,8 @@ MAINTENANCE_PREVIEW_LEASE = "Maintenance preview"
 DUPLICATE_PREVIEW_BODY_MAX = 1024 * 1024
 DUPLICATE_FILES = "duplicate_files"
 WORKFLOW_STORAGE = "workflow_storage"  # applied by py/api/workflow_storage.py
-PREVIEW_OPERATIONS = MAINTENANCE_OPERATIONS + (DUPLICATE_FILES,)
+# rotated_logs (#329, py/api/log_cleanup.py) reviews log files, not records.
+PREVIEW_OPERATIONS = MAINTENANCE_OPERATIONS + (DUPLICATE_FILES, ROTATED_LOGS)
 # Room left over beyond what a step writes, so a disk is never filled to 0.
 DISK_MARGIN_BYTES = 16 * 2**20
 # The concept's Maintenance row titles, which name each operation's job.
@@ -391,6 +395,8 @@ class MaintenanceRoutesMixin:
             return await self.preview_duplicate_files(options)
         if not isinstance(options, dict) or options:
             return _invalid(f"{operation} takes no options")
+        if operation == ROTATED_LOGS:
+            return await self.preview_log_cleanup()
         db = self.db
         identity = self._database_identity(db)
         try:
@@ -492,6 +498,17 @@ class MaintenanceRoutesMixin:
         if refused is not None:
             return refused
         store = self._maintenance_plans
+        if plan.operation == ROTATED_LOGS:
+            # Log files only: no database identity, backup or disk check.
+            try:
+                job = self._start_log_cleanup(plan)
+            except JobBusy as busy:
+                return busy_response(busy)  # the token stays usable
+            # Same loop turn as the peek and the start: the runner has not run.
+            store.consume(token, plan.operation, job_id=job.id)
+            return web.json_response(
+                {"success": True, "job": job.summary()}, status=202
+            )
         db = self.db
         if plan.db_identity != self._database_identity(db):
             store.discard(token)

tests/test_api_log_cleanup.py

@@ -0,0 +1,419 @@
+"""Reviewed rotated-log cleanup as a maintenance plan (#329, py/api/log_cleanup.py).
+
+``POST /maintenance/preview {operation: "rotated_logs"}`` lists exactly the
+rotated copies Rule R allows and writes nothing; ``POST /maintenance/apply``
+deletes exactly those as a ``maintenance`` job (admission ``read``), or
+nothing, failing ``plan-changed``, when any of them changed after the review.
+
+Every test runs on a real ``PromptManagerLogger`` whose log folder is a
+temporary folder, never the real one.
+"""
+
+import asyncio
+import json
+import logging
+import ntpath
+import os
+import posixpath
+import re
+import sys
+import threading
+import unittest
+import unittest.mock as mock
+
+sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+
+from py.api.maintenance_plans import PlanStore  # noqa: E402
+from utils import logging_config  # noqa: E402
+from utils.logging_config import PromptManagerLogger, get_logger_manager  # noqa: E402
+
+try:
+    from tests.open_handles import assert_closed  # noqa: E402
+    from tests.test_api_maintenance import MaintenanceAPITestCase  # noqa: E402
+except ImportError:  # discovered with tests/ as the top-level directory
+    from open_handles import assert_closed  # noqa: E402
+    from test_api_maintenance import MaintenanceAPITestCase  # noqa: E402
+
+WAIT = 10
+PREVIEW = "/prompt_manager/maintenance/preview"
+APPLY = "/prompt_manager/maintenance/apply"
+CHANGED = "The log files changed since the review; nothing was deleted. Review again."
+MEDIA = "Deletes only the listed log files. No image, video or library record changes."
+_WINDOWS_ABSOLUTE = re.compile(r"^[A-Za-z]:[\\/]")
+
+
+def _strings(value):
+    if isinstance(value, str):
+        yield value
+    elif isinstance(value, dict):
+        for item in value.values():
+            yield from _strings(item)
+    elif isinstance(value, (list, tuple)):
+        for item in value:
+            yield from _strings(item)
+
+
+class LogCleanupTestCase(MaintenanceAPITestCase):
+    async def get_application(self):
+        app = await super().get_application()
+        package = os.path.join(self.tmpdir, "pkg")
+        os.makedirs(os.path.join(package, "utils"))
+        fake_file = os.path.join(package, "utils", "logging_config.py")
+        with mock.patch.object(logging_config, "__file__", fake_file):
+            self.manager = object.__new__(PromptManagerLogger)  # bypass singleton
+            self.manager.__init__()
+        self.addCleanup(self._restore_global_logging)
+        self.manager.update_config({"console_logging": False})
+        self._only_this_thread()
+        self.log_dir = str(self.manager.log_dir)
+        self.app_logger = logging.getLogger("prompt_manager.log_cleanup_test")
+        self.app_logger.info("active log line")
+        self.api._get_logger_manager = lambda: self.manager
+        self.outside = os.path.join(self.tmpdir, "link-targets")
+        os.makedirs(self.outside)
+        return app
+
+    def _only_this_thread(self):
+        """Only this test's records reach the temporary log (not other threads')."""
+        this_thread = threading.get_ident()
+        for handler in self.manager.logger.handlers:
+            handler.filters.clear()
+            handler.addFilter(lambda record: record.thread == this_thread)
+
+    def _restore_global_logging(self):
+        for handler in logging.getLogger("prompt_manager").handlers[:]:
+            handler.close()
+        assert_closed(self, self.log_dir)
+        get_logger_manager()._setup_loggers()
+
+    def path(self, name):
+        return os.path.join(self.log_dir, name)
+
+    def write(self, name, data=b"rotated\n"):
+        with open(self.path(name), "wb") as handle:
+            handle.write(data)
+
+    def symlink(self, name):
+        target = os.path.join(self.outside, "secret.txt")
+        with open(target, "wb") as handle:
+            handle.write(b"secret " * 100)
+        try:
+            os.symlink(target, self.path(name))
+        except (OSError, NotImplementedError):  # pragma: no cover - no privilege
+            return False
+        return True
+
+    def names(self):
+        return sorted(os.listdir(self.log_dir))
+
+    def snapshot(self):
+        """Every entry but the active log, with its bytes (None for a folder)."""
+        state = {}
+        for name in self.names():
+            if name == "prompt_manager.log":
+                continue
+            path = self.path(name)
+            if os.path.islink(path):
+                state[name] = ("link", os.readlink(path))
+            elif os.path.isdir(path):
+                state[name] = None
+            else:
+                with open(path, "rb") as handle:
+                    state[name] = handle.read()
+        return state
+
+    def seed(self):
+        """CUJ 5's folder: three rotated copies, a .bak, a folder and a link."""
+        self.write("prompt_manager.log.1", b"a" * 1000)
+        self.write("prompt_manager.log.2", b"b" * 2000)
+        self.write("prompt_manager.log.3", b"c" * 3000)
+        self.write("prompt_manager.log.bak", b"mine")
+        os.makedirs(self.path("prompt_manager.log.9"))
+        return self.symlink("prompt_manager.log.4")
+
+    async def preview(self, status=200, **body):
+        return await self.post(
+            PREVIEW, {"operation": "rotated_logs", "options": {}, **body}, status
+        )
+
+    async def apply(self, token, status=202):
+        return await self.post(APPLY, {"token": token}, status)
+
+    async def run_apply(self, plan):
+        body = await self.apply(plan["token"])
+        job = self.api._jobs.get(body["job"]["id"])
+        await asyncio.wait_for(asyncio.shield(job.task), WAIT)
+        return body["job"], job
+
+
+class TestPreview(LogCleanupTestCase):
+    async def test_preview_lists_only_rotated_copies(self):
+        linked = self.seed()
+        plan = await self.preview()
+        self.assertEqual(
+            set(plan),
+            {
+                "success",
+                "token",
+                "operation",
+                "expires_at",
+                "scope",
+                "protected",
+                "backup",
+                "media",
+                "details",
+            },
+        )
+        self.assertEqual(plan["operation"], "rotated_logs")
+        self.assertEqual(
+            plan["scope"], {"count": 3, "label": "3 rotated log copies · 5.9 KB"}
+        )
+        self.assertEqual(
+            [row["label"] for row in plan["details"]],
+            ["prompt_manager.log.1", "prompt_manager.log.2", "prompt_manager.log.3"],
+        )
+        self.assertRegex(
+            plan["details"][2]["detail"], r"^2\.9 KB · \d{4}-\d\d-\d\d \d\d:\d\d$"
+        )
+        reasons = ["Kept: the active log"]
+        if linked:
+            reasons.append("Kept: 1 link")
+        reasons.append("Kept: 2 other files")
+        self.assertEqual(
+            plan["protected"], {"count": len(reasons) + 1, "reasons": reasons}
+        )
+        self.assertEqual(
+            plan["backup"],
+            {"policy": "none", "destination_label": None, "expected_bytes": None},
+        )
+        self.assertEqual(plan["media"], {"deletes_files": True, "label": MEDIA})
+        self.assertTrue(plan["expires_at"].endswith("+00:00"))
+        self.assertNotIn("mtime_ns", json.dumps(plan))
+
+    async def test_preview_writes_nothing(self):
+        self.seed()
+        before = self.snapshot()
+        await self.preview()
+        self.assertEqual(self.snapshot(), before)
+
+    async def test_preview_has_no_paths(self):
+        self.seed()
+        plan = await self.preview()
+        for text in _strings(plan):
+            self.assertFalse(posixpath.isabs(text), text)
+            self.assertFalse(ntpath.isabs(text), text)
+            self.assertIsNone(_WINDOWS_ABSOLUTE.match(text), text)
+
+    async def test_preview_rejects_non_empty_options(self):
+        for options in ({"all": True}, [], "x"):
+            with self.subTest(options=options):
+                reply = await self.preview(status=400, options=options)
+                self.assertEqual(reply["code"], "invalid-request")
+
+    async def test_preview_too_large_is_413(self):
+        self.seed()
+        self.api._maintenance_plans = PlanStore(max_bytes=10)
+        reply = await self.preview(status=413)
+        self.assertEqual(
+            reply,
+            {
+                "success": False,
+                "code": "too-large",
+                "error": "Too many log files to review at once.",
+            },
+        )
+
+    async def test_empty_folder_plan_has_scope_zero(self):
+        plan = await self.preview()
+        self.assertEqual(plan["scope"], {"count": 0, "label": "No rotated log copies"})
+        self.assertEqual(plan["details"], [])
+        self.assertEqual(
+            plan["protected"], {"count": 1, "reasons": ["Kept: the active log"]}
+        )
+
+    async def test_preview_refused_while_an_exclusive_job_runs(self):
+        async with self.api._jobs.hold(
+            "restore", "Database restore", admission="exclusive"
+        ):
+            reply = await self.preview(status=409)
+        self.assertEqual(reply["code"], "busy")
+
+
+class TestApply(LogCleanupTestCase):
+    async def test_apply_deletes_exactly_the_reviewed_files(self):
+        linked = self.seed()
+        plan = await self.preview()
+        summary, job = await self.run_apply(plan)
+        self.assertEqual(summary["kind"], "maintenance")
+        self.assertEqual(summary["title"], "Rotated log copies")
+        self.assertEqual(summary["admission"], "read")
+        self.assertFalse(summary["cancellable"])
+        self.assertEqual(summary["scope"], {"operation": "rotated_logs"})
+        self.assertEqual(job.state, "finished", job.log)
+        self.assertEqual(
+            job.counters,
+            {"changed": 3, "protected": plan["protected"]["count"], "errors": 0},
+        )
+        expected = [
+            "prompt_manager.log",
+            "prompt_manager.log.9",
+            "prompt_manager.log.bak",
+        ]
+        if linked:
+            expected.append("prompt_manager.log.4")
+        self.assertEqual(self.names(), sorted(expected))
+        self.assertEqual(job.status_line, "Deleted 3 rotated log copies")
+        report = json.dumps(job.report())
+        self.assertNotIn(self.tmpdir, report)
+
+    async def test_apply_rows_name_each_file(self):
+        self.seed()
+        plan = await self.preview()
+        _summary, job = await self.run_apply(plan)
+        self.assertEqual(
+            job.outcomes["changed"],
+            [
+                {
+                    "path": "prompt_manager.log.1",
+                    "root": "",
+                    "root_index": None,
+                    "detail": "Deleted · 1000 bytes",
+                },
+                {
+                    "path": "prompt_manager.log.2",
+                    "root": "",
+                    "root_index": None,
+                    "detail": "Deleted · 2.0 KB",
+                },
+                {
+                    "path": "prompt_manager.log.3",
+                    "root": "",
+                    "root_index": None,
+                    "detail": "Deleted · 2.9 KB",
+                },
+            ],
+        )
+        log = "\n".join(job.log)
+        for n in (1, 2, 3):
+            self.assertIn(f"prompt_manager.log.{n}", log)
+
+    async def test_apply_after_rollover_fails_plan_changed_and_deletes_nothing(self):
+        self.seed()
+        plan = await self.preview()
+        handler = next(
+            h
+            for h in self.manager.logger.handlers
+            if isinstance(h, logging.FileHandler)
+        )
+        handler.acquire()
+        try:
+            handler.doRollover()  # every listed name now holds another file
+        finally:
+            handler.release()
+        before = self.snapshot()
+        _summary, job = await self.run_apply(plan)
+        self.assertEqual(job.state, "failed")
+        self.assertEqual(job.scope["failure"], "plan-changed")
+        self.assertEqual(job.status_line, CHANGED)
+        self.assertEqual(job.counters["changed"], 0)
+        self.assertEqual(self.snapshot(), before)
+
+    async def test_apply_reports_a_file_in_use(self):
+        self.seed()
+        plan = await self.preview()
+        real_unlink = os.unlink
+        held = self.path("prompt_manager.log.2")
+
+        def unlink(path, *args, **kwargs):
+            if os.fspath(path) == held:
+                error = PermissionError(
+                    13,
+                    "The process cannot access the file because it is being "
+                    "used by another process",
+                    held,
+                )
+                error.winerror = 32
+                raise error
+            return real_unlink(path, *args, **kwargs)
+
+        with mock.patch.object(logging_config.os, "unlink", unlink):
+            _summary, job = await self.run_apply(plan)
+        self.assertEqual(job.counters["changed"], 2)
+        self.assertEqual(job.counters["errors"], 1)
+        [row] = job.outcomes["errors"]
+        self.assertEqual(row["path"], "prompt_manager.log.2")
+        self.assertIn("being used by another process", row["detail"])
+        self.assertNotIn(self.tmpdir, json.dumps(job.report()))
+        self.assertIn("prompt_manager.log.2", self.names())
+        self.assertEqual(
+            job.status_line, "Deleted 2 rotated log copies, 1 could not be deleted"
+        )
+
+    async def test_token_is_single_use(self):
+        self.seed()
+        plan = await self.preview()
+        summary, _job = await self.run_apply(plan)
+        again = await self.apply(plan["token"], 409)
+        self.assertEqual(again["code"], "plan-used")
+        self.assertEqual(
+            again["job"], {"id": summary["id"], "title": "Rotated log copies"}
+        )
+
+    async def test_apply_runs_beside_a_scan(self):
+        self.seed()
+        plan = await self.preview()
+        async with self.api._jobs.hold("scan", "Metadata scan", admission="records"):
+            _summary, job = await self.run_apply(plan)
+        self.assertEqual(job.state, "finished", job.log)
+        self.assertNotIn("prompt_manager.log.1", self.names())
+
+    async def test_apply_refused_while_restore_runs(self):
+        self.seed()
+        plan = await self.preview()
+        async with self.api._jobs.hold(
+            "restore", "Database restore", admission="exclusive"
+        ) as restore:
+            busy = await self.apply(plan["token"], 409)
+        self.assertEqual(busy["code"], "busy")
+        self.assertEqual(
+            busy["running"], {"id": restore.id, "title": "Database restore"}
+        )
+        self.assertIn("prompt_manager.log.1", self.names())
+        # The refused apply kept the token.
+        _summary, job = await self.run_apply(plan)
+        self.assertEqual(job.state, "finished", job.log)
+
+    async def test_apply_refused_beside_another_maintenance_job(self):
+        self.seed()
+        plan = await self.preview()
+        async with self.api._jobs.hold(
+            "maintenance", "Optimize database", admission="records"
+        ):
+            busy = await self.apply(plan["token"], 409)
+        self.assertEqual(busy["code"], "busy")
+
+    async def test_active_log_survives_and_keeps_growing(self):
+        self.seed()
+        plan = await self.preview()
+        await self.run_apply(plan)
+        self.app_logger.info("written after the cleanup")
+        with open(self.path("prompt_manager.log"), "rb") as handle:
+            content = handle.read()
+        self.assertIn(b"active log line", content)
+        self.assertIn(b"written after the cleanup", content)
+
+    async def test_an_unexpected_failure_fails_the_job_without_details(self):
+        self.seed()
+        plan = await self.preview()
+        with mock.patch.object(
+            self.manager, "delete_rotated", side_effect=RuntimeError(self.tmpdir)
+        ):
+            with self.assertLogs("prompt_manager", "ERROR"):
+                _summary, job = await self.run_apply(plan)
+        self.assertEqual(job.state, "failed")
+        self.assertNotIn(self.tmpdir, json.dumps(job.report()))
+        self.assertEqual(job.status_line, "The log cleanup failed.")
+
+
+if __name__ == "__main__":
+    unittest.main()