feat(20-01): add removeVuState function to useVuHelpers

- Add removeVuState callback to clean up vuStates entries
- Export removeVuState alongside updateVuState
- Uses functional setState for React state batching compatibility
- Maintains immutability by creating shallow copy before deletion

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

jam-ui/src/hooks/useVuHelpers.js

@@ -103,6 +103,14 @@ export default function useVuHelpers() {
     }));
   }, []);
 
+  const removeVuState = useCallback((mixerId) => {
+    setVuStates(prev => {
+      const newState = { ...prev };
+      delete newState[mixerId];
+      return newState;
+    });
+  }, []);
+
   const updateVU3 = useCallback(
     (mixer, leftValue, leftClipping, rightValue, rightClipping) => {
       const fqId = createQualifiedId(mixer);
@@ -175,6 +183,7 @@ export default function useVuHelpers() {
     // React-like components and functions
     VuMeter: VuMeterComponent,
     updateVuState,
+    removeVuState,
     vuStates,
 
     // Legacy functions for backward compatibility