fix(28-02): check pendingUpdates in getLevelSnapshot

The vuStore RAF loop only runs with subscribers, but SessionTrackVU
uses direct polling without subscribing. Changed getLevelSnapshot to
check pendingUpdates first for immediate access to latest VU data.

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

jam-ui/src/stores/vuStore.js

@@ -97,12 +97,14 @@ export const vuStore = {
   /**
    * Get snapshot of single mixer's VU level
    * More efficient for components that only need one mixer's data
+   * Checks both pending updates and flushed levels for immediate access
    *
    * @param {string} mixerId - Qualified mixer ID
    * @returns {Object|null} - { level, clipping, timestamp } or null
    */
   getLevelSnapshot(mixerId) {
-    return vuLevels[mixerId] || null;
+    // Check pending updates first (most recent), then flushed levels
+    return pendingUpdates[mixerId] || vuLevels[mixerId] || null;
   },
 
   /**