1a476c49c1
- Full CRUD + broadcast/unpin/activate/deactivate endpoints
- Admin auth required on all endpoints (get_current_admin_user)
- Broadcast cooldown (60s) on all mass operation endpoints
- Cached Bot singleton to prevent aiohttp session leaks
- Guard against deleting active pinned messages (409 Conflict)
- Route ordering: /active/* before /{message_id}/* to prevent path conflicts
- Pydantic schemas with proper validation (file_id max_length=255)