feat: add waveform generation and timeline display

Co-authored-by: Cursor <cursoragent@cursor.com>

src/lib/stores/videoSession.svelte.ts

@@ -1,7 +1,7 @@
 import type { VideoMetadata } from '$lib/bindings/video';
 import { startDownload } from '$lib/bindings/video';
 import type { ThumbnailSpritesheet } from '$lib/bindings/mediaAnalysis';
-import { extractKeyframes } from '$lib/bindings/mediaAnalysis';
+import { extractKeyframes, extractWaveform } from '$lib/bindings/mediaAnalysis';
 
 export type SessionStatus = 'idle' | 'resolving' | 'ready' | 'error';
 export type DownloadStatus = 'idle' | 'downloading' | 'complete' | 'failed';
@@ -79,12 +79,22 @@ export function reset() {
 }
 
 async function triggerPostDownloadProcessing(filePath: string) {
-  try {
-    session.keyframePositions = await extractKeyframes(filePath);
-  } catch (e) {
-    console.error('Keyframe extraction failed:', e);
+  const [keyframes, waveform] = await Promise.allSettled([
+    extractKeyframes(filePath),
+    extractWaveform(filePath, 8000),
+  ]);
+
+  if (keyframes.status === 'fulfilled') {
+    session.keyframePositions = keyframes.value;
+  } else {
+    console.error('Keyframe extraction failed:', keyframes.reason);
+  }
+
+  if (waveform.status === 'fulfilled') {
+    session.waveformPeaks = waveform.value;
+  } else {
+    console.error('Waveform extraction failed:', waveform.reason);
   }
-  // Waveform and thumbnails will be added in Tasks 10 and 11
 }
 
 export async function beginDownload() {