fix: clear stale CSS properties and subtitle state on style/media update

- Remove CSS properties absent from subsequent subtitle style updates
- Broadcast subtitle:set clear when media path changes
- Preserve launcher lifecycle ownership for already-managed overlay apps
- Clamp negative autoplay current time to zero
- Reject blank subminerBinaryPath values via parseNonEmptyString
- Log and rethrow legacy config migration errors instead of swallowing
- Normalize modifier aliases (e.g. CommandOrControl) in keybinding display

launcher/mpv.ts

@@ -1016,7 +1016,7 @@ export async function startOverlay(
     env: buildAppEnv(process.env, target.env),
   });
   attachAppProcessLogging(state.overlayProc);
-  if (appAlreadyRunning) {
+  if (appAlreadyRunning && !(state.overlayManagedByLauncher && state.appPath === appPath)) {
     log(
       'debug',
       args.logLevel,