Fix duplicate caching (#62)

* Fix duplicate/redundant caching issue

- Add get_background_cached_data() and is_background_data_available() methods to CacheManager
- Update sports managers to use background service cache instead of individual caching
- Ensure consistent cache key generation between background service and managers
- Eliminate redundant API calls by making Recent/Upcoming managers cache consumers
- Fix cache miss issues where TTL < update interval

This addresses GitHub issue #57 by implementing a cleaner caching architecture
where the background service is the primary data source and managers are cache consumers.

* Update remaining sports managers to use background service cache

- Update NHL managers to use background service cache
- Update NCAA Football managers to use background service cache
- Update NCAA Hockey managers to use background service cache
- Update MLB managers to use background service cache for Recent/Upcoming

All sports managers now use the new caching architecture to eliminate
duplicate caching and redundant API calls.

* cache improvements

* updated cache manager

src/nba_managers.py

@@ -12,6 +12,7 @@ from src.cache_manager import CacheManager
 from src.config_manager import ConfigManager
 from src.odds_manager import OddsManager
 from src.background_data_service import get_background_service
+from src.background_cache_mixin import BackgroundCacheMixin
 import pytz
 
 # Import the API counter function from web interface
@@ -32,7 +33,7 @@ logging.basicConfig(
     datefmt='%Y-%m-%d %H:%M:%S'
 )
 
-class BaseNBAManager:
+class BaseNBAManager(BackgroundCacheMixin):
     """Base class for NBA managers with common functionality."""
     # Class variables for warning tracking
     _no_data_warning_logged = False
@@ -317,11 +318,16 @@ class BaseNBAManager:
             return None
 
     def _fetch_data(self, date_str: str = None) -> Optional[Dict]:
-        """Fetch data using shared data mechanism."""
-        if isinstance(self, NBALiveManager):
-            return self._fetch_nba_api_data(use_cache=False)
-        else:
-            return self._fetch_nba_api_data(use_cache=True)
+        """
+        Fetch data using background service cache first, fallback to direct API call.
+        This eliminates redundant caching and ensures Recent/Upcoming managers
+        use the same data source as the background service.
+        """
+        return self._fetch_data_with_background_cache(
+            sport_key='nba',
+            api_fetch_method=self._fetch_nba_api_data,
+            live_manager_class=NBALiveManager
+        )
 
     def _fetch_odds(self, game: Dict) -> None:
         """Fetch odds for a specific game if conditions are met."""