- Import CommandHistory and all 4 command classes from new modules
- hitTest() with 8px EDGE for resize-left/resize-right/move zones
- _hasOverlap() check for time range collision on same track
- snapToBeat() with 0.1s threshold and calibrationOffset
- _setupInteractions() with mousedown/mousemove/keydown listeners
- _startMove(): live drag preview, snap on mouseup, overlap rejection
- _startResize(): left/right edge handles, 0.5s min duration, snap
- handleDrop(): place block from palette with crypto.randomUUID()
- Keyboard: Delete, Ctrl+Z (undo), Ctrl+Shift+Z / Ctrl+Y (redo)
- app.js: dragstart on palette, dragover/dragleave/drop on canvas
- Ghost block rendered during dragover for visual feedback
- Resize handle indicators drawn on selected block
- Create lightsync/frontend/timeline/timeline.js with TimelineCanvas class
- Per-device horizontal tracks with track headers and time axis
- HiDPI canvas rendering with devicePixelRatio handling
- Waveform peaks background layer, beat marks overlay, cue block rendering
- Playback cursor synced to audio.currentTime via requestAnimationFrame
- Auto-scroll when cursor approaches right edge
- Mouse wheel scrolling on timeline canvas
- loadTracks(), loadWaveform(), loadBeats() data loading methods
- Empty state messages when no devices or audio loaded
- Add timeline CSS to style.css (toolbar, canvas, inspector strip, snap button)
- Wire timeline into app.js: import, initTimeline(), zoom/beat-offset/snap controls
- Remove old animation-grid click listener (element no longer exists in main-area)
- Populate animation palette dynamically in sidebar with 7 animation types
