- Lists, Tasks, Tags CRUD endpoints with soft-delete
- Sync endpoints (GET since + POST batch with idempotency keys)
- WS ticket endpoint (ephemeral nonce, 30s TTL, single use)
- Auth middleware on all endpoints via getAuthenticatedUser()
- BOLA prevention: userId check on every entity operation
- Zod strict schemas for input validation
- Filters and sorting on task listing
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>