feat(studio): export AudioWaveform and useMountEffect

Exports two components for reuse by consumers:
- AudioWaveform: real PCM waveform visualization with fake fallback
- useMountEffect: useEffect(fn, []) wrapper for mount-only effects

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

packages/studio/src/index.ts

@@ -12,6 +12,7 @@ export {
   PreviewPanel,
   VideoThumbnail,
   CompositionThumbnail,
+  AudioWaveform,
   useTimelinePlayer,
   usePlayerStore,
   liveTime,
@@ -28,6 +29,7 @@ export { FileTree } from "./components/editor/FileTree";
 export { StudioApp } from "./App";
 
 // Hooks
+export { useMountEffect } from "./hooks/useMountEffect";
 export { useCodeEditor } from "./hooks/useCodeEditor";
 export type { OpenFile, UseCodeEditorReturn } from "./hooks/useCodeEditor";
 export { useElementPicker } from "./hooks/useElementPicker";

packages/studio/src/player/index.ts

@@ -5,6 +5,7 @@ export { Timeline } from "./components/Timeline";
 export { PreviewPanel } from "./components/PreviewPanel";
 export { VideoThumbnail } from "./components/VideoThumbnail";
 export { CompositionThumbnail } from "./components/CompositionThumbnail";
+export { AudioWaveform } from "./components/AudioWaveform";
 
 // Hooks
 export { useTimelinePlayer } from "./hooks/useTimelinePlayer";