refactor: add folder rename configuration and service

Add configurable folder rename patterns via settings with anime_folder_rename_regex and custom_pattern options. Integrate into SerieScanner and SeriesApp for consistent episode organization.

src/config/settings.py

@@ -169,5 +169,23 @@ class Settings(BaseSettings):
             ]
         return [origin.strip() for origin in raw.split(",") if origin.strip()]
 
+    @property
+    def scan_key_overrides(self) -> dict[str, str]:
+        """Return scan key overrides from config.json.
+        
+        Maps folder names to provider keys for cases where auto-generated
+        keys from folder names are incorrect.
+        
+        Returns:
+            Dict mapping folder names to provider keys.
+        """
+        from src.server.services.config_service import ConfigService
+        try:
+            config_service = ConfigService()
+            config = config_service.load_config()
+            return config.scan_key_overrides or {}
+        except Exception:
+            return {}
+
 
 settings = Settings()