- Align REST API contracts for Dashboard (threads list, detail, SSE)
- Add content resolution from CAS in thread show + API responses
- Rename dataWatcher → threadsJsonWatcher in SSE routes
- Update docs (CLAUDE.md, architecture.md, skill.ts) to reflect CAS storage
- Zero .data.jsonl code paths in production code
- All 166 tests pass, bun run check clean
Refs #155, closes#160
小橘 <xiaoju@shazhou.work>