feat: Complete Ableton-style track layout redesign

Track height & spacing improvements:
- Increased DEFAULT_TRACK_HEIGHT from 180px to 240px for vertical controls
- Increased MIN_TRACK_HEIGHT from 60px to 120px
- Increased MAX_TRACK_HEIGHT from 300px to 400px
- Added COLLAPSED_TRACK_HEIGHT constant (48px)
- Reduced control panel gap from 8px to 6px for tighter spacing
- Added min-h-0 and overflow-hidden to prevent flex overflow
- Optimized fader container with max-h-[140px] constraint

Clip-style waveform visualization (Ableton-like):
- Wrapped waveform canvas in visible "clip" container
- Added border, rounded corners, and shadow for clip identity
- Added 16px clip header bar showing track name
- Implemented hover state for better interactivity
- Added gradient background from-foreground/5 to-transparent

Track height resize functionality:
- Added draggable bottom-edge resize handle
- Implemented cursor-ns-resize with hover feedback
- Constrain resizing to MIN/MAX height range
- Real-time height updates with smooth visual feedback
- Active state highlighting during resize

Effects section visual integration:
- Changed from solid background to gradient (from-muted/80 to-muted/60)
- Reduced device rack height from 192px to 176px for better proportion
- Improved visual hierarchy and connection to track row

Flexible VerticalFader component:
- Changed from fixed h-32 (128px) to flex-1 layout
- Added min-h-[80px] and max-h-[140px] constraints
- Allows parent container to control actual height
- Maintains readability and proportions at all sizes

CSS enhancements (globals.css):
- Added .track-clip-container utility class
- Added .track-clip-header utility class
- Theme-aware clip styling for light/dark modes
- OKLCH color space for consistent appearance

Visual results:
- Professional DAW appearance matching Ableton Live
- Clear clip/region boundaries for audio editing
- Better proportions for vertical controls (240px tracks)
- Resizable track heights (120-400px range)
- Improved visual hierarchy and organization

Files modified:
- types/track.ts (height constants)
- components/tracks/Track.tsx (layout + clip styling + resize)
- components/ui/VerticalFader.tsx (flexible height)
- app/globals.css (clip styling)

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

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

components/ui/VerticalFader.tsx

@@ -107,7 +107,7 @@ export function VerticalFader({
       <div
         ref={trackRef}
         onMouseDown={handleMouseDown}
-        className="relative w-8 h-32 bg-muted rounded cursor-pointer select-none overflow-hidden"
+        className="relative w-8 flex-1 min-h-[80px] max-h-[140px] bg-muted rounded cursor-pointer select-none overflow-hidden"
       >
         {/* Level Meter Background (green/yellow/red gradient) */}
         <div