fix: moveToGroup should rename traces, not merge them

Changed from apiCall('merge_trace', ...) to updateTraceProfileGroup(name=targetGroup.name).
This just changes the trace profile name to join the target group,
without actually merging trace data together.

src/views/PeopleView.vue

@@ -1814,43 +1814,37 @@ async function batchMoveFaces() {
 async function moveToGroup(targetGroup: any) {
   showMoveFacesModal.value = false
   
-  const targetTraceId = targetGroup.trace_ids?.[0]
-  if (!targetTraceId) {
-    alert('Target group has no traces')
-    return
-  }
-  
-  const targetTrace = clusterTracesMap.value[String(targetTraceId)]
-  const targetFileUuid = targetTrace?.file_uuid
-  if (!targetFileUuid) {
-    alert('Target trace has no file_uuid')
-    return
-  }
-  
   const traceList: { file_uuid: string; trace_id: number }[] = []
   for (const key of selectedFaces.value) {
     const [file_uuid, trace_id] = key.split(':')
     traceList.push({ file_uuid, trace_id: parseInt(trace_id) })
   }
   
+  if (!traceList.length) return
   if (!confirm(`Move ${traceList.length} trace(s) to "${targetGroup.name}"?`)) return
   
   operationLoading.value = true
   operationMessage.value = `Moving ${traceList.length} trace(s)...`
   
+  // Group by file_uuid for batch update
+  const byFile: Record<string, number[]> = {}
   for (const t of traceList) {
+    if (!byFile[t.file_uuid]) byFile[t.file_uuid] = []
+    byFile[t.file_uuid].push(t.trace_id)
+  }
+  
+  for (const [fileUuid, traceIds] of Object.entries(byFile)) {
     try {
-      await apiCall('merge_trace', { 
-        file_uuid: t.file_uuid, 
-        source_id: t.trace_id, 
-        target_id: targetTraceId 
-      })
+      await updateTraceProfileGroup(fileUuid, traceIds, { name: targetGroup.name })
     } catch (e) {
-      console.error('Move trace failed:', t, e)
+      console.error('Move traces failed:', fileUuid, traceIds, e)
     }
   }
   
-  removeTracesFromCache(selectedFaces.value)
+  // Refresh cluster results
+  if (selectedFileUuid.value) {
+    await loadClusterResults()
+  }
   
   operationLoading.value = false
   operationMessage.value = ''