Review Checklist:
[x] Supabase state migration - atomic task acquisition verified
[x] E2E project proof - all 7 stages driven via API
[x] QA multi-check - 5 check types implemented and tested
[x] Heartbeat fix - direct Supabase insert every 15s
[x] Claude execution - real Anthropic API call with model selection
[x] Skills enforcement - mismatch correctly blocks task execution