feat: implement Fitbit OAuth, Garmin MFA, and optimize segment discovery

- Add Fitbit authentication flow (save credentials, OAuth callback handling)
- Implement Garmin MFA support with successful session/cookie handling
- Optimize segment discovery with new sampling and activity query services
- Refactor database session management in discovery API for better testability
- Enhance activity data parsing for charts and analysis
- Update tests to use testcontainers and proper dependency injection
- Clean up repository by ignoring and removing tracked transient files (.pyc, .db)

FitnessSync/backend/src/api/config_routes.py

@@ -7,15 +7,11 @@ import json
 
 from ..services.postgresql_manager import PostgreSQLManager
 from ..utils.config import config
+from .status import get_db
 
 router = APIRouter()
 logger = logging.getLogger(__name__)
 
-def get_db():
-    db_manager = PostgreSQLManager(config.DATABASE_URL)
-    with db_manager.get_db_session() as session:
-        yield session
-
 @router.post("/setup/load-consul-config")
 def load_consul_config(db: Session = Depends(get_db)):
     logger = logging.getLogger(__name__)