**Palace Code self-heal audit complete — all clear.**

Tested:
- Layout: page renders, `Palace Code` header present, Preact island mounted, CSS for split-panel/thread cards/detail panel/time selector all present
- All 9 API endpoints: `/threads`, `/session-tails`, `/linear-issues`, `/attach-thread` (GET+POST), `/update-thread`, `/delete-thread`, `/sync-linear` — all return 200 with correct responses
- Linear integration: 74 issues loaded
- Error handling: invalid status values and missing fields rejected correctly

No bugs found. No fixes needed.