fix: correct updateClusterAfterMerge to trigger computed update

Problem:
- Previous commit tried to splice computed property (clusterAsPending)
- Computed properties cannot be modified directly
- Need to update underlying data (clusterResultsCache)

Solution:
- Remove incorrect clusterAsPending.value.splice()
- Trigger reactive update via clusterResultsCache reassignment
- clusterAsPending computed will auto-update

Technical details:
- Vue computed properties are read-only
- Must modify underlying reactive data
- Reassignment triggers computed recalculation

src/views/PeopleView.vue

@@ -1611,14 +1611,11 @@ function updateClusterAfterMerge(sourceGroupId: string, targetGroupId: string) {
     
     const idx = clusters.findIndex((c: any) => c.identity_uuid === sourceGroupId)
     if (idx >= 0) {
-      clusters.splice(idx, 1)  // ← Remove empty source group
+      clusters.splice(idx, 1)  // Remove empty source group from cache
     }
-  }
-  
-  // Also remove from clusterAsPending computed
-  const idx2 = clusterAsPending.value.findIndex((c: any) => c.identity_uuid === sourceGroupId)
-  if (idx2 >= 0) {
-    clusterAsPending.value.splice(idx2, 1)
+    
+    // Trigger computed property update
+    clusterResultsCache.value = { ...clusterResultsCache.value }
   }
 }