feat: implement Ableton Live-style DAW layout

Major UX refactor to match professional DAW workflows (Ableton/Bitwig):

**Layout Changes:**
- Removed sidebar completely
- Track actions moved to header toolbar (Add/Import/Clear All)
- Each track now shows its own devices/effects in the track strip
- Master section moved to bottom footer area
- Full-width waveform display

**Track Strip (left panel):**
- Track name (editable inline)
- Color indicator
- Collapse/Solo/Mute/Delete buttons
- Volume slider with percentage
- Pan slider with L/C/R indicator
- Collapsible "Devices" section showing track effects
  - Shows effect count in header
  - Each effect card shows: name, enable/disable toggle, remove button
  - Effects are colored based on enabled/disabled state
  - Click to expand/collapse devices section

**Master Section (bottom):**
- Transport controls (Play/Pause/Stop) with timeline
- Master volume control
- Master effects placeholder (to be implemented)

**Benefits:**
- True DAW experience like Ableton Live
- Each track is self-contained with its own effect chain
- No context switching between tabs
- Effects are always visible for each track
- More screen space for waveforms
- Professional mixer-style layout

Note: Effects are visible but not yet applied to audio - that's next!

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

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

components/tracks/Track.tsx

@@ -23,6 +23,8 @@ export interface TrackProps {
   onNameChange: (name: string) => void;
   onSeek?: (time: number) => void;
   onLoadAudio?: (buffer: AudioBuffer) => void;
+  onToggleEffect?: (effectId: string) => void;
+  onRemoveEffect?: (effectId: string) => void;
 }
 
 export function Track({
@@ -41,12 +43,15 @@ export function Track({
   onNameChange,
   onSeek,
   onLoadAudio,
+  onToggleEffect,
+  onRemoveEffect,
 }: TrackProps) {
   const canvasRef = React.useRef<HTMLCanvasElement>(null);
   const containerRef = React.useRef<HTMLDivElement>(null);
   const fileInputRef = React.useRef<HTMLInputElement>(null);
   const [isEditingName, setIsEditingName] = React.useState(false);
   const [nameInput, setNameInput] = React.useState(String(track.name || 'Untitled Track'));
+  const [showDevices, setShowDevices] = React.useState(true);
   const inputRef = React.useRef<HTMLInputElement>(null);
 
   const handleNameClick = () => {
@@ -378,6 +383,61 @@ export function Track({
                   : `R${Math.round(track.pan * 100)}`}
               </span>
             </div>
+
+            {/* Devices/Effects Section */}
+            <div className="pt-2 border-t border-border">
+              <button
+                onClick={() => setShowDevices(!showDevices)}
+                className="flex items-center justify-between w-full text-xs font-medium text-foreground hover:text-primary transition-colors mb-2"
+              >
+                <span>Devices ({track.effectChain.effects.length})</span>
+                {showDevices ? (
+                  <ChevronDown className="h-3.5 w-3.5" />
+                ) : (
+                  <ChevronRight className="h-3.5 w-3.5" />
+                )}
+              </button>
+
+              {showDevices && (
+                <div className="space-y-1">
+                  {track.effectChain.effects.length === 0 ? (
+                    <div className="text-xs text-muted-foreground text-center py-2">
+                      No devices
+                    </div>
+                  ) : (
+                    track.effectChain.effects.map((effect) => (
+                      <div
+                        key={effect.id}
+                        className={cn(
+                          'flex items-center justify-between px-2 py-1.5 rounded text-xs',
+                          effect.enabled
+                            ? 'bg-accent/50 text-foreground'
+                            : 'bg-muted/50 text-muted-foreground'
+                        )}
+                      >
+                        <span className="truncate">{effect.name}</span>
+                        <div className="flex items-center gap-1">
+                          <button
+                            onClick={() => onToggleEffect?.(effect.id)}
+                            className="hover:text-primary"
+                            title={effect.enabled ? 'Disable' : 'Enable'}
+                          >
+                            {effect.enabled ? '●' : '○'}
+                          </button>
+                          <button
+                            onClick={() => onRemoveEffect?.(effect.id)}
+                            className="hover:text-destructive"
+                            title="Remove"
+                          >
+                            ×
+                          </button>
+                        </div>
+                      </div>
+                    ))
+                  )}
+                </div>
+              )}
+            </div>
           </>
         )}
       </div>