feat:實作預約系統 — 時段管理、預約生命週期與前端整合

後端：
- 新增 course_schedules / bookings migration（含索引）
- BookingStatus / ScheduleStatus PHP BackedEnum
- CourseSchedule / Booking Model（七狀態機 VALID_TRANSITIONS）
- ScheduleController、ProviderBookingController、MemberBookingController
- 雙層名額驗證（API 層快速失敗 + DB lockForUpdate 防超賣）
- 24h 取消截止、pending 不佔位設計
- ExpirePendingBookings（每小時）/ CompleteFinishedBookings（每日）Scheduler
- Docker cron 配置、CACHE_STORE 改為 file 修正 502

前端：
- 課程詳情頁加入時段選擇與預約流程
- 我的預約頁（展開式卡片、狀態說明、連結課程詳情）
- Coach 時段管理（上午/下午時間選擇器、新課程引導）
- Coach 預約管理（依課程分組、待確認徽章）
- Navbar 新增「我的預約」與「時段/預約管理」入口
- 密碼格式提示與即時比對

OpenSpec：
- booking-system change 歸檔至 archive/2026-05-12-booking-system
- 新增 specs/course-scheduling 與 specs/booking-lifecycle 主規格

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

frontend/src/router/index.js

@@ -11,7 +11,8 @@ const routes = [
   { path: '/login',          component: () => import('../views/LoginView.vue') },
   { path: '/register',       component: () => import('../views/RegisterView.vue') },
   { path: '/auth/callback',  component: () => import('../views/AuthCallbackView.vue') },
-  { path: '/profile',        component: () => import('../views/ProfileView.vue'), meta: { requiresAuth: true } },
+  { path: '/profile',     component: () => import('../views/ProfileView.vue'),    meta: { requiresAuth: true } },
+  { path: '/my-bookings', component: () => import('../views/MyBookingsView.vue'), meta: { requiresAuth: true } },
 
   // Coach (public)
   { path: '/coach/login',    component: () => import('../views/coach/LoginView.vue') },
@@ -26,6 +27,8 @@ const routes = [
       { path: 'offers/new',      component: () => import('../views/coach/OfferFormView.vue') },
       { path: 'offers/:id/edit', component: () => import('../views/coach/OfferFormView.vue') },
       { path: 'profile',         component: () => import('../views/coach/ProfileView.vue') },
+      { path: 'schedules',       component: () => import('../views/coach/ScheduleManagerView.vue') },
+      { path: 'bookings',        component: () => import('../views/coach/BookingManagerView.vue') },
     ],
   },