fix: transport AppImage args via env and gate restart on app-ping

- Transport Linux AppImage CLI args through SUBMINER_APP_ARGC/ARG_* env vars instead of argv
- Add --app-ping command to probe single-instance lock ownership (exit 0 = running, 1 = not)
- Gate manual restart: poll app-ping until old app releases lock, then until new app owns it
- Preserve user-paused playback when disarming the auto-play-ready gate on restart
- Snapshot subtitles before connection side effects (sub-visibility hide) can suppress them
- Reapply overlay bounds after first show for Hyprland compatibility

src/cli/args.test.ts

@@ -236,6 +236,11 @@ test('hasExplicitCommand and shouldStartApp preserve command intent', () => {
   assert.equal(shouldStartApp(help), false);
   assert.equal(shouldRunSettingsOnlyStartup(help), false);
 
+  const appPing = parseArgs(['--app-ping']);
+  assert.equal(appPing.appPing, true);
+  assert.equal(hasExplicitCommand(appPing), true);
+  assert.equal(shouldStartApp(appPing), false);
+
   const youtubePlay = parseArgs(['--youtube-play', 'https://youtube.com/watch?v=abc']);
   assert.equal(commandNeedsOverlayStartupPrereqs(youtubePlay), true);