#3673 On Windows, v3 outbox tests time out on a writer lock held by a dead fake pid

Windows Compatibility on main d77cf3ec (run 39448217856) failed one test: v3 outbox: a sweep that deleted a writer's chunks before it prepared is caught before the append (integration/datastore_v3_outbox_test.ts:415). The same test passed on a75c633d, and the only change between them is test expectations in two extension test files, so it is intermittent in CI.

On the local Windows 11 VM (win-test) it fails every time, and so do five other tests in that file (4 passed, 6 failed, including serve's retake lands what a writer between its two holds left). The error for the line-415 test:

V3WriterBusyError: Another swamp process is writing the v3 datastore at C:\Users[REDACTED]\AppData\Local\Temp\swamp-usecase-v3-...\datastore (test@WINTEST, pid 99999999). Caused by: LockTimeoutError: Lock _control\writer held by test@WINTEST (pid 99999999), timed out after 64246ms.

The test plants a writer lock for pid 99999999 that is meant to read as dead and be taken over; on Windows the takeover does not happen and the acquire waits out its timeout. Likely the writer-liveness check (see swamp-club#3564) judges a nonexistent pid as alive on Windows, or the test's dead-pid assumption does not hold there. Repro: win-test . deno test -A --unstable-bundle integration/datastore_v3_outbox_test.ts --filter 'caught before the append'. Found while confirming swamp-club#3666; unrelated to it.