feat: persist search session across page navigation

- Save messages to localStorage when leaving search page
- Restore messages when returning to search page
- Clear session on newChat()
- Session includes: messages, conversationId, fileUuidCache, mode

src/views/SearchView.vue

@@ -286,6 +286,7 @@
 
 <script setup lang="ts">
 import { ref, nextTick, computed, onMounted, onUnmounted } from 'vue'
+import { onBeforeRouteLeave } from 'vue-router'
 import { apiCall } from '@/api'
 import { getApiBase } from '@/api/config'
 import VideoPlayer from '../components/VideoPlayer.vue'
@@ -325,6 +326,7 @@ const modes = [
 const mode = ref(localStorage.getItem('ms_chat_mode_v1') || 'keyword')
 const query = ref('')
 const messages = ref<ChatMessage[]>([])
+const SESSION_STORAGE_KEY = 'ms_search_session'
 const thumbs = thumbnailsCache
 const sending = ref(false)
 const messagesEl = ref<HTMLElement | null>(null)
@@ -598,6 +600,24 @@ onMounted(async () => {
   await ensureFiles()
   loadHistory()
   loadBookmarks()
+  
+  // Restore session from localStorage
+  try {
+    const saved = localStorage.getItem(SESSION_STORAGE_KEY)
+    if (saved) {
+      const session = JSON.parse(saved)
+      if (session.messages && Array.isArray(session.messages)) {
+        messages.value = session.messages
+        conversationId.value = session.conversationId || ''
+        fileUuidCache.value = session.fileUuidCache || []
+        mode.value = session.mode || mode.value
+        localStorage.setItem('ms_chat_mode_v1', mode.value)
+      }
+    }
+  } catch (e) {
+    console.error('[SearchView] Failed to restore session:', e)
+  }
+  
   // Load search config for visual search parameters
   try {
     const base = getApiBase()
@@ -616,7 +636,43 @@ onMounted(async () => {
     console.error('[SearchView] Failed to load search config:', e)
   }
 })
-onUnmounted(() => document.removeEventListener('click', closeDropdowns))
+
+onBeforeRouteLeave(() => {
+  // Save current session to localStorage
+  try {
+    if (messages.value.length > 0) {
+      const session = {
+        messages: messages.value,
+        conversationId: conversationId.value,
+        fileUuidCache: fileUuidCache.value,
+        mode: mode.value,
+        savedAt: Date.now()
+      }
+      localStorage.setItem(SESSION_STORAGE_KEY, JSON.stringify(session))
+    }
+  } catch (e) {
+    console.error('[SearchView] Failed to save session:', e)
+  }
+})
+
+onUnmounted(() => {
+  document.removeEventListener('click', closeDropdowns)
+  // Save session on unmount as well
+  try {
+    if (messages.value.length > 0) {
+      const session = {
+        messages: messages.value,
+        conversationId: conversationId.value,
+        fileUuidCache: fileUuidCache.value,
+        mode: mode.value,
+        savedAt: Date.now()
+      }
+      localStorage.setItem(SESSION_STORAGE_KEY, JSON.stringify(session))
+    }
+  } catch (e) {
+    console.error('[SearchView] Failed to save session:', e)
+  }
+})
 
 function scrollToBottom() {
   nextTick(() => {
@@ -633,6 +689,8 @@ function newChat() {
   conversationId.value = ''
   fileUuidCache.value = []
   sending.value = false
+  // Clear saved session
+  localStorage.removeItem(SESSION_STORAGE_KEY)
 }
 
 function startNewChat() {
@@ -1109,7 +1167,11 @@ async function sendMessage() {
       
       const sceneResults = filteredScenes.map((s: any) => {
         const sceneIndex = s.index ?? s.scene_index ?? 0
-        const frameNumber = s.frame_number ?? Math.round((s.timestamp_sec || 0) * 30)
+        const fileInfo = filesCache.value.find((f: any) => (f.file_uuid || f.uuid) === s.file_uuid)
+        const fps = fileInfo?.fps || 30
+        const ts = s.timestamp_sec ?? (s.frame_number != null ? s.frame_number / fps : 0)
+        const frameNumber = s.frame_number ?? Math.round(ts * fps)
+        const windowSec = 5
         
         // Build bilingual description
         let vlmDesc = s.vlm_description || ''
@@ -1129,10 +1191,10 @@ async function sendMessage() {
           ...s,
           search_query: q,
           source_type: 'scene',
-          start_frame: frameNumber,
+          start_frame: Math.max(0, frameNumber - Math.round(windowSec * fps)),
-          end_frame: frameNumber + 30,
+          end_frame: frameNumber + Math.round(windowSec * fps),
-          start_time: s.timestamp_sec,
+          start_time: Math.max(0, ts - windowSec),
-          end_time: (s.timestamp_sec || 0) + 1,
+          end_time: ts + windowSec,
           summary: vlmDesc ? `[SCENE] ${vlmDesc}` : `Scene ${sceneIndex}`,
           text_content: textContent,
           similarity: s.score ?? null,
@@ -1144,7 +1206,11 @@ async function sendMessage() {
       })
       
       const traceResults = filteredTraces.map((t: any) => {
-        const frame = t.start_frame ?? t.best_face_frame ?? 0
+        const fileInfo = filesCache.value.find((f: any) => (f.file_uuid || f.uuid) === t.file_uuid)
+        const fps = fileInfo?.fps || 30
+        const frame = t.start_frame ?? t.best_face_frame ?? t.frame_number ?? Math.round((t.timestamp_sec || 0) * fps)
+        const ts = t.start_time ?? t.timestamp_sec ?? (frame / fps)
+        const windowSec = 5
         
         // Build bilingual description
         let vlmDesc = t.vlm_description || ''
@@ -1162,8 +1228,10 @@ async function sendMessage() {
           ...t,
           search_query: q,
           source_type: 'trace',
-          start_frame: frame,
+          start_frame: Math.max(0, frame - Math.round(windowSec * fps)),
-          end_frame: frame + 30,
+          end_frame: frame + Math.round(windowSec * fps),
+          start_time: Math.max(0, ts - windowSec),
+          end_time: ts + windowSec,
           summary: vlmDesc || t.text_content || 'Person appearance',
           text_content: textContent,
           similarity: t.score ?? null,