🐛 | Fix prefetch bug (str vs int), move json import to module level, add missing type hints

config.py

@@ -84,13 +84,13 @@ def save_volume(volume: int) -> None:
     save_config(dict(SETTINGS))
 
 
-def save_setting(key: str, value) -> None:
+def save_setting(key: str, value: object) -> None:
     """Persist a single setting and update the in-memory SETTINGS dict."""
     SETTINGS[key] = value
     save_config(dict(SETTINGS))
 
 
-def get_setting(key: str):
+def get_setting(key: str) -> object:
     """Return a setting value from the in-memory dict."""
     return SETTINGS.get(key, DEFAULT_CONFIG.get(key))