feat: 添加 Tauri Mac 原生应用支持

- 新增 mac-app/ 目录：Tauri 项目结构（Rust 外壳 + sidecar 进程管理）
- 前端添加 Tauri 环境检测，API 调用和 WebSocket 自动适配
- 后端支持 MEETING_DATA_DIR 环境变量指定数据目录
- 新增 /api/meetings/{id}/retranscribe 接口用于重新转录
- 修复轮询超时：2分钟→30分钟，适配长音频
- 添加 .gitignore 排除构建产物

frontend/src/api/meeting.js

@@ -1,6 +1,7 @@
 import axios from 'axios'
 
-const API_BASE = '/api'
+const isTauri = typeof window !== 'undefined' && '__TAURI_INTERNALS__' in window
+const API_BASE = isTauri ? 'http://localhost:8501/api' : '/api'
 
 const api = axios.create({
   baseURL: API_BASE,

frontend/src/pages/Upload.jsx

@@ -87,7 +87,7 @@ export default function UploadPage() {
       
       await pollMeetingStatus(result.meeting_id, (status) => {
         if (status === 'processing') {
-          setTranscribeProgress(prev => Math.min(prev + 5, 90))
+          setTranscribeProgress(prev => Math.min(prev + 2, 95))
         }
       })
       
@@ -111,7 +111,9 @@ export default function UploadPage() {
 
   const connectWebSocket = () => {
     const sessionId = `realtime_${Date.now()}_${Math.random().toString(36).slice(2, 8)}`
-    const ws = new WebSocket(`ws://localhost:8501/ws/realtime/${sessionId}`)
+    const isTauri = typeof window !== 'undefined' && '__TAURI_INTERNALS__' in window
+    const wsHost = isTauri ? 'localhost:8501' : window.location.host
+    const ws = new WebSocket(`ws://${wsHost}/ws/realtime/${sessionId}`)
 
     ws.onopen = () => {
       setWsConnected(true)

frontend/src/store/useAppStore.js

@@ -1,5 +1,8 @@
 import { create } from 'zustand'
 
+const isTauri = typeof window !== 'undefined' && '__TAURI_INTERNALS__' in window
+const API_BASE = isTauri ? 'http://localhost:8501' : ''
+
 export const useAppStore = create((set, get) => ({
   // 会议列表
   meetings: [],
@@ -38,7 +41,7 @@ export const useAppStore = create((set, get) => ({
   refreshMeetings: async () => {
     set({ loading: true, error: null })
     try {
-      const res = await fetch('/api/meetings')
+      const res = await fetch(`${API_BASE}/api/meetings`)
       const data = await res.json()
       set({
         meetings: data.meetings || [],
@@ -59,7 +62,7 @@ export const useAppStore = create((set, get) => ({
   fetchMeetingDetail: async (meetingId) => {
     set({ loading: true, error: null })
     try {
-      const res = await fetch(`/api/meetings/${meetingId}`)
+      const res = await fetch(`${API_BASE}/api/meetings/${meetingId}`)
       const data = await res.json()
       set({ currentMeeting: data, loading: false })
       return data
@@ -101,7 +104,7 @@ export const useAppStore = create((set, get) => ({
           set({ loading: false, isTranscribing: false })
           reject(new Error('Network error'))
         }
-        xhr.open('POST', '/api/meetings/upload')
+        xhr.open('POST', `${API_BASE}/api/meetings/upload`)
         xhr.send(formData)
       })
     } catch (err) {
@@ -112,7 +115,7 @@ export const useAppStore = create((set, get) => ({
 
   // 轮询会议状态直到完成
   pollMeetingStatus: async (meetingId, onStatusChange) => {
-    const maxAttempts = 60  // 最多轮询60次（约2分钟）
+    const maxAttempts = 600  // 最多轮询600次（约30分钟）
     let attempts = 0
 
     const poll = async () => {
@@ -122,7 +125,7 @@ export const useAppStore = create((set, get) => ({
       attempts++
 
       try {
-        const res = await fetch(`/api/meetings/${meetingId}`)
+        const res = await fetch(`${API_BASE}/api/meetings/${meetingId}`)
         const data = await res.json()
         
         onStatusChange?.(data.status)
@@ -132,7 +135,7 @@ export const useAppStore = create((set, get) => ({
         }
 
         // 继续轮询
-        await new Promise(r => setTimeout(r, 2000))  // 每2秒轮询一次
+        await new Promise(r => setTimeout(r, 3000))  // 每3秒轮询一次
         return poll()
       } catch (err) {
         throw err