fix: remove unused imports and bare exception aliases (pyflakes F401/F841)

Remove unused imports across 86 files in src/, web_interface/, test/,
and scripts/ using autoflake. No logic changes — only dead import
statements and unused names in from-imports are removed.

Also remove bare exception aliases where the variable is never
referenced in the handler body:
- src/cache/disk_cache.py: except (IOError, OSError, PermissionError) as e
- src/cache_manager.py: except (OSError, IOError, PermissionError) as perm_error
- src/plugin_system/resource_monitor.py: except Exception as e
- web_interface/app.py: except Exception as read_err

86 files changed, 205 lines removed, 18 pre-existing test failures unchanged.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/base_classes/data_sources.py

@@ -6,11 +6,10 @@ to support different APIs and data providers.
 """
 
 from abc import ABC, abstractmethod
-from typing import Dict, Any, Optional, List
+from typing import Dict, List
 import requests
 import logging
-from datetime import datetime, timedelta
-import time
+from datetime import datetime
 
 class DataSource(ABC):
     """Abstract base class for data sources."""
@@ -35,17 +34,14 @@ class DataSource(ABC):
     @abstractmethod
     def fetch_live_games(self, sport: str, league: str) -> List[Dict]:
         """Fetch live games for a sport/league."""
-        pass
     
     @abstractmethod
     def fetch_schedule(self, sport: str, league: str, date_range: tuple) -> List[Dict]:
         """Fetch schedule for a sport/league within date range."""
-        pass
     
     @abstractmethod
     def fetch_standings(self, sport: str, league: str) -> Dict:
         """Fetch standings for a sport/league."""
-        pass
     
     def get_headers(self) -> Dict[str, str]:
         """Get headers for API requests."""