**Goal:** Refactor the GarminSync backend to remove the local database and use an in-memory solution for job tracking and CentralDB for all other data.

**Completed Steps:**
1.  Updated the spec files (`plan.md`, `tasks.md`, `quickstart.md`).
2.  Removed all database-related code and dependencies.
3.  Implemented an in-memory store for job tracking.
4.  Refactored the services (`auth_service.py`, `central_db_service.py`, `garmin_activity_service.py`, `garmin_health_service.py`, `garmin_workout_service.py`, `sync_status_service.py`).
5.  Updated the API endpoints in `garmin_sync.py`.
6.  Fixed `ImportError` in `rate_limiter.py`.
7.  Added `tenacity` to dependencies.
8.  Fixed dependency injection issue in `garmin_sync.py`.
9.  Verified that the application runs.

**Current Step:** All planned tasks are completed.

**Next Action:**
Review the remaining tasks in `tasks.md` and decide on the next steps.