feat: apply defaultTrackHeight and defaultZoom settings

- Modified createTrack and createTrackFromBuffer to accept height parameter
- Updated useMultiTrack to pass height when creating tracks
- Applied settings.ui.defaultTrackHeight when adding new tracks
- Applied settings.editor.defaultZoom for initial zoom state
- Removed duplicate useSettings hook declaration in AudioEditor
- New tracks now use configured default height from settings

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

lib/hooks/useMultiTrack.ts

@@ -6,14 +6,14 @@ export function useMultiTrack() {
   // Note: localStorage persistence disabled in favor of IndexedDB project management
   const [tracks, setTracks] = useState<Track[]>([]);
 
-  const addTrack = useCallback((name?: string) => {
-    const track = createTrack(name);
+  const addTrack = useCallback((name?: string, height?: number) => {
+    const track = createTrack(name, undefined, height);
     setTracks((prev) => [...prev, track]);
     return track;
   }, []);
 
-  const addTrackFromBuffer = useCallback((buffer: AudioBuffer, name?: string) => {
-    const track = createTrackFromBuffer(buffer, name);
+  const addTrackFromBuffer = useCallback((buffer: AudioBuffer, name?: string, height?: number) => {
+    const track = createTrackFromBuffer(buffer, name, undefined, height);
     setTracks((prev) => [...prev, track]);
     return track;
   }, []);