feat(ui): SoC Refactoring & Config Validation

- Theme Context ausgelagert (ThemeContext.tsx + useDarkMode.ts)
- Config Validation mit TMDB-API-Key Pflicht (config_validation.py)
- Cache Key Centralization (cache/keys.py)
- CD-Ripping mit abcde implementiert (Worker)
- Docker Compose mit Healthchecks & LOG_LEVEL
- ROADMAP.md & SAVEPOINT.md aktualisiert

docker/api/clients/tmdb.py

@@ -22,7 +22,8 @@ class TMDBClient:
     
     def _request(self, endpoint: str, params: Dict = None) -> Optional[Dict]:
         """Mache API-Request mit Caching."""
-        cache_key = f"tmdb:{endpoint}:{params or {}}"
+        from cache.keys import generate_tmdb_key
+        cache_key = generate_tmdb_key(endpoint, params)
         
         cached = get(cache_key)
         if cached: