Palace Code self-heal audit complete — **all 12 tests passed, nothing broken**.

### What Was Tested
- Main page renders with correct layout (split-panel, thread list, detail panel)
- All 9 API endpoints responded correctly:
  - `/code/api/threads` — 5 threads returned
  - `/code/api/session-tails` — recent log entries returned
  - `/code/api/linear-issues` — 80+ Linear issues
  - `/code/api/attach-thread` — attachment list
  - `/code/api/sync-linear` — sync works
  - `/code/api/update-thread` — update + 400 validation working
  - `/code/api/delete-thread` — delete works
  - `/api/heartbeats` — all 7 heartbeats reported
- Source code reviewed: Dashboard, DetailPanel, ThreadCard, StatusBadge, thread-store, web-bridges — all correct
- 5 threads in Redis: 4 `replied`, 1 `archived`, all with session files and cost data

No fixes needed. Service is healthy.