ci(portability): cut the Windows Python suite time at its causes (#487) (#490)

* test: list the slowest tests on request and stop waiting 30 s on a held WAL (#487)

PM_TEST_SLOWEST=N makes tests/run_suite.py list the N slowest tests.
Three history tests restored while their own read held a snapshot, so
each publish sat out the 30 s WAL-truncate wait; they now use a short wait.
Temporary diagnostics for the Windows timings ride along in this commit.

* test(lora): check Windows folder rules without asking the network (#487)

On Windows ntpath.realpath looks up \\server\share and waited about 2.8 s
per test for a host that does not exist. The guard tests now use the
lexical NT path rules, which is what they already ran on Linux and macOS.

* ci(portability): keep Windows test files on the work disk (#487)

The Windows runner's TEMP is on C:, where a flush took about 6 ms and a test
database's create-to-delete about 111 ms; on D: the same took 0.5 ms and
23 ms. The job now points TEMP/TMP at RUNNER_TEMP and lists the 40 slowest
tests. The fake HTTPS handlers get a TLS context that reads no certificate
store, and the missing-share tests name localhost instead of an unknown
server. The temporary diagnostics are removed.

* ci(portability): spell the Windows test TEMP by its short name (#487)

The runner's own TEMP was C:\Users\RUNNER~1\..., so tests met 8.3 short
names in every temp path. The folder on D: keeps that when the disk has
short names, and the step logs which spelling it got. TESTING.md notes
that the slowest list is not printed when a job is cancelled.

* ci(portability): switch on 8.3 names for the Windows test TEMP (#487)

D: made no short names (run 40922502209 logged the long spelling), so
the step now switches them on for D: before it creates the folder, and
warns when the folder still has no short name.

.github/workflows/portability.yml

@@ -51,5 +51,27 @@ jobs:
           python -m pip install --upgrade pip
           pip install -r requirements-dev.txt
 
+      # 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
+      # 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
+      # and paths still have to be resolved. D: makes no short names by default
+      # (run 40922502209), so they are switched on for it first.
+      - name: Keep test files on the work disk (Windows)
+        if: runner.os == 'Windows'
+        shell: pwsh
+        run: |
+          fsutil 8dot3name set D: 0
+          $folder = New-Item -ItemType Directory -Force -Path (Join-Path $env:RUNNER_TEMP "PromptManagerTests")
+          $short = (New-Object -ComObject Scripting.FileSystemObject).GetFolder($folder.FullName).ShortPath
+          Write-Output "test TEMP: $short (long name $($folder.FullName))"
+          if ($short -eq $folder.FullName) { Write-Output "::warning::D: gave the test TEMP no 8.3 short name" }
+          "TEMP=$short" >> $env:GITHUB_ENV
+          "TMP=$short" >> $env:GITHUB_ENV
+
       - name: Run tests
+        env:
+          PM_TEST_SLOWEST: "40"
         run: python -m tests.run_suite -v