PR #1214 CI follow-up: server startup lock and preview fixture comments
Date: 2026-08-26 (Asia/Shanghai)
Fixed source commit: e1b1a6903b38f19caf996e056448481b93e4b2ba

Witnessed red (GitHub job 98147650320, synthetic merge 970f1932):
- test798 discovered and executed all 76 server test files.
- Only server/src/task-lifecycle-watcher.test.ts failed (4 pass, 1 fail).
- The live-watcher test's immediate fixture INSERT failed at line 168 with
  SQLITE_BUSY / "database is locked" while a real Hub child was starting.
- Full downloaded job log: /tmp/pr1214-server-unit.log

Isolation evidence:
- PR #1214 had not changed the watcher/product path.
- An exact old-head 6916943720527ba25fc259cf8d3ec3d2e52acb58 test798
  Docker rerun passed all 76 files and its password-floor witnessed-red.
- Therefore the old no-timeout test demonstrably admits both outcomes under
  startup scheduling; the CI failure is the witnessed SQLITE_BUSY outcome.

Deterministic fix:
- The test-owned child Database now sets PRAGMA busy_timeout = 5000 before its
  fixture INSERT, so it waits for startHub's short startup migration writer.
- No server production behavior changed.
- Corrected the package-owned fixture comments in test750 and test751 from
  preview.33 to their executable preview.34 value.

Focused Docker gates, run sequentially after the prior gate passed:

1. test798 exact server unit domain, source e1b1a690:
   executed_files=76 discovered_files=76 failed_files=0
   MUTATION_RED registration-password-floor-weakened rc=1
   RESULT: PASS
   Full output: /tmp/pr1214-test798-lockfix.log

2. test750 Linux Codex co-presence, source e1b1a690:
   Summary: PASS (10 groups, 0 failures; all validation ran inside Docker)
   Full output: /tmp/pr1214-test750-comments.log

3. test751 Windows portable logic:
   15 pass, 3 platform skips, 0 fail; tsc --noEmit exited zero
   Full output: /tmp/pr1214-test751-comments.log
