fix: align youtube playback with shared overlay startup

src/core/services/youtube/retime.ts

@@ -0,0 +1,11 @@
+export async function retimeYoutubeSubtitle(input: {
+  primaryPath: string;
+  secondaryPath: string | null;
+}): Promise<{ ok: boolean; path: string; strategy: 'none'; message: string }> {
+  return {
+    ok: true,
+    path: input.primaryPath,
+    strategy: 'none',
+    message: `Using downloaded subtitle as-is${input.secondaryPath ? ' (no automatic retime enabled)' : ''}`,
+  };
+}