feat:實作通知系統 — 站內通知、Email 通知、Polling 機制

後端
- 新增 6 個 Notification class（預約建立/確認/拒絕/取消/完成、收到評價），database + mail 雙 channel
- 新增 NotificationController（list / unread-count / markRead / markAllRead / destroy）
- 整合通知觸發至 MemberBookingController、ProviderBookingController、CompleteFinishedBookings、ReviewController
- 新增 notifications / jobs / failed_jobs migration
- Docker Compose 加入 queue-worker、mailpit service
- DivingOffer 補上 provider() 關聯

前端
- 新增 notificationStore（Polling 30s/60s 自適應 + Page Visibility API）
- 新增 NotificationBell（未讀 Badge）、NotificationDrawer（側邊通知中心）
- main.js：auth store init 前置於 router.use()，修正 beforeEach guard 時序問題
- notificationAxios：依路徑動態選擇 member/coach token
- NotificationDrawer：改用 new URL().pathname 提取 action_url 路徑

OpenSpec
- 歸檔 notification-system change
- 同步 notification-core / notification-email / notification-triggers specs 至主規格
- 更新 booking-lifecycle / review-lifecycle spec（補充通知觸發 requirement）

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

frontend/src/App.vue

@@ -1,21 +1,10 @@
 <script setup>
-import { computed, onMounted } from 'vue'
-import { useAuthStore } from './stores/auth'
-import { useCoachAuthStore } from './stores/coachAuth'
-import { useAdminAuthStore } from './stores/adminAuth'
+import { computed } from 'vue'
 import { useRoute } from 'vue-router'
 import NavBar from './components/NavBar.vue'
+import NotificationDrawer from './components/NotificationDrawer.vue'
 
-const auth      = useAuthStore()
-const coachAuth = useCoachAuthStore()
-const adminAuth = useAdminAuthStore()
-const route     = useRoute()
-
-onMounted(() => {
-  auth.init()
-  coachAuth.init()
-  adminAuth.init()
-})
+const route = useRoute()
 
 const isBackofficePage = computed(() =>
   route.path.startsWith('/coach') || route.path.startsWith('/admin')
@@ -26,5 +15,6 @@ const isBackofficePage = computed(() =>
   <div class="min-h-screen bg-gray-50">
     <NavBar v-if="!isBackofficePage" />
     <RouterView />
+    <NotificationDrawer />
   </div>
 </template>