fix: resolve wifi crashes, shell injections, race conditions, and add debug mode

- Remove transient NEED_AUTH/DISCONNECTED error paths from wifi connect
- Guard double-callback in connect_wifi_bssid/connect_wifi_with_password
- Shell-quote user paths in wallpaper, screenshot, screenrecorder services
- Fix OSD hide-timer use-after-free and applet_window stale source ID
- Fix brightness poll timer leak on read failure
- Fix spotlight search stale idle source removal
- Lock dbusmenu _cache mutation under _registry_lock
- Fix entry.revision written outside _registry_lock scope
- Add fabric-cli exec wrapper for lock screen (lock_screen.lock())
- Replace hyprlock with lock screen in power menu and dropdown
- Add debug mode toggle in settings (controls log verbosity)
- Add diagnostic logging to globalmenu click chain

src/services/config.py

@@ -59,6 +59,15 @@ class ConfigService:
         """Set a config value (local state only)."""
         self._config[key] = value
 
+    def save(self) -> None:
+        """Persist current in-memory config to disk."""
+        try:
+            doc = self._dict_to_toml(self._config)
+            with open(self._config_file, "w") as f:
+                toml_dump(doc, f)
+        except Exception as e:
+            logger.error(f"[ConfigService] Failed to save config: {e}")
+
     def register_reload_callback(
         self, callback: Callable[[Dict[str, Any], Dict[str, Any]], None]
     ) -> None: