fix: resolve TypeScript compilation errors

Fixes:
- VideoPlayer.vue: restore allTags, filteredMarks, marksByTag (removed by mistake)
- PeopleView.vue: fix frameTime scope in playFaceDetailVideo catch block
- Both errors caused white screen on build failure

Root cause:
1. visibleTags duplicate declaration (old + new logic)
2. frameTime undefined in catch block (scope issue)

Solution:
1. Keep allTags/filteredMarks/marksByTag (needed in template)
2. Keep visibleTags (new logic for processor toggles)
3. Move frameTime calculation to correct scope in catch block

src/stores/agentStore.ts

@@ -0,0 +1,48 @@
+import { ref } from 'vue'
+
+export const agentTip = ref<string>('')
+export const showAgentTip = ref(false)
+export const agentSuggestions = ref<string[]>([])
+export const discoveryTip = ref<string>('')
+export const userBehavior = ref({
+  hasUsedKeywordSearch: false,
+  hasUsedSemanticSearch: false,
+  hasUsedPeopleSearch: false,
+  hasUsedFileFilter: false,
+  hasUsedContextMenu: false,
+  hasViewedPersonDetails: false,
+  hasBindedFace: false,
+  hasUsedSearchHistory: false,
+  hasUsedBookmark: false
+})
+
+export function showTip(message: string, duration = 5000) {
+  agentTip.value = message
+  showAgentTip.value = true
+  setTimeout(() => {
+    showAgentTip.value = false
+  }, duration)
+}
+
+export function showDiscovery(message: string, duration = 8000) {
+  discoveryTip.value = message
+  setTimeout(() => {
+    discoveryTip.value = ''
+  }, duration)
+}
+
+export function trackBehavior(action: keyof typeof userBehavior.value) {
+  userBehavior.value[action] = true
+  localStorage.setItem('momentry_user_behavior', JSON.stringify(userBehavior.value))
+}
+
+export function loadUserBehavior() {
+  const saved = localStorage.getItem('momentry_user_behavior')
+  if (saved) {
+    try {
+      userBehavior.value = JSON.parse(saved)
+    } catch (e) {
+      console.error('Failed to load user behavior:', e)
+    }
+  }
+}