fix: prevent event bubbling on sidebar track controls

Added stopPropagation to track controls container to prevent click events on sliders and buttons from bubbling up to the track selection handler.

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

components/layout/SidePanel.tsx

@@ -210,7 +210,7 @@ export function SidePanel({
                         </div>
 
                         {/* Track Controls - Always visible */}
-                        <div className="space-y-2">
+                        <div className="space-y-2" onClick={(e) => e.stopPropagation()}>
                           {/* Volume */}
                           <div className="space-y-1">
                             <div className="flex items-center justify-between">