Stale FavoriteRepo docs with old GitHub IDs (e.g. from deleted or
recreated repos) surfaced as duplicates once the prefix scan started
returning every doc.
All database reads and writes now run off the main thread via a
dedicated worker, eliminating IndexedDB overhead from the frame budget.
- Create data.worker.ts exposing the Data class via Comlink
- Refactor data.ts to export a Comlink-wrapped proxy and a standalone
generateId() pure function (workers can't expose sync methods cleanly)
- Update all 10 call sites to import generateId directly instead of
calling data.generateId()
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
