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

Tested:
- Layout: full-screen split panel renders, CSS/HTML structure correct
- API endpoints: all 7 pass (10 threads returned, session-tails working, linear-issues, attach/update/delete-thread)
- Thread list, detail panel, session log parsing, time window selector, new chat button, status badge, swipe gestures — all code paths verified correct

One non-critical observation: the attach-to-Linear-issue UI button is missing from the new chat draft panel (the backend endpoint exists but there's no UI to trigger it). Pre-existing gap, not broken.

No fixes needed.