fix: align youtube playback with shared overlay startup

src/core/services/youtube/generate.ts

@@ -0,0 +1,25 @@
+import type { YoutubeFlowMode } from '../../../types';
+import type { YoutubeTrackOption } from './track-probe';
+import { downloadYoutubeSubtitleTrack, downloadYoutubeSubtitleTracks } from './track-download';
+
+export function isYoutubeGenerationMode(mode: YoutubeFlowMode): boolean {
+  return mode === 'generate';
+}
+
+export async function acquireYoutubeSubtitleTrack(input: {
+  targetUrl: string;
+  outputDir: string;
+  track: YoutubeTrackOption;
+  mode: YoutubeFlowMode;
+}): Promise<{ path: string }> {
+  return await downloadYoutubeSubtitleTrack(input);
+}
+
+export async function acquireYoutubeSubtitleTracks(input: {
+  targetUrl: string;
+  outputDir: string;
+  tracks: YoutubeTrackOption[];
+  mode: YoutubeFlowMode;
+}): Promise<Map<string, string>> {
+  return await downloadYoutubeSubtitleTracks(input);
+}