feat: 即時預約聊天室（realtime booking chat）

## 新增功能
- 會員與教練在 confirmed 預約期間可互傳文字與圖片訊息
- Presence Channel 顯示對方在線狀態（即時加入/離線）
- 已讀回執：對方讀取訊息後即時更新
- 預約完成（completed）後訊息封存唯讀
- 圖片上傳使用 intervention/image 處理（移除 EXIF、限制尺寸、強制重新編碼）

## 通知系統
- 收到新訊息時 Bell Icon 即時更新（NotificationCreated via private channel）
- 預約列表卡片顯示未讀角標（GET /api/bookings/messages/unread-counts 批次查詢）
- 瀏覽器分頁在背景時推送 Web Notification

## 基礎建設
- 引入 Laravel Reverb 作為自架 WebSocket 伺服器
- docker-compose 新增 reverb service（連接 proxy_net，供 NPM 代理）
- 前端安裝 laravel-echo + pusher-js，初始化 Echo plugin
- Dockerfile 補 GD JPEG/WebP/FreeType 支援

## 清理
- 移除 test_broadcast.php 與 resources/js/echo.js（Blade 殘留）
- 移除 /ping、/testpost 測試路由
- channels.php 改用 class-based 授權語法，移除 debug log
- BookingChat.vue otherType 提取為 computed 消除重複
- docker-entrypoint.sh 健康檢查改用 env var 取代硬編碼密碼

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

routes/api.php

@@ -1,5 +1,6 @@
 <?php
 
+use Illuminate\Support\Facades\Broadcast;
 use Illuminate\Support\Facades\Route;
 use App\Http\Controllers\API\AuthController;
 use App\Http\Controllers\API\DivingOfferController;
@@ -14,12 +15,10 @@ use App\Http\Controllers\API\CourseImageController;
 use App\Http\Controllers\API\AdminStatsController;
 use App\Http\Controllers\API\AdminUserController;
 use App\Http\Controllers\API\AdminOfferController;
+use App\Http\Controllers\API\BookingMessageController;
 use App\Http\Controllers\API\NotificationController;
 
-// 這裡可以定義 API 路由，例如：
-Route::get('/ping', function () {
-    return response()->json(['message' => 'pong']);
-});
+Broadcast::routes(['middleware' => ['auth:sanctum']]);
 
 // 潛水課程（公開）
 Route::get('/diving-offers', [DivingOfferController::class, 'index']);
@@ -27,14 +26,6 @@ Route::get('/diving-offers/{id}', [DivingOfferController::class, 'show']);
 Route::get('/diving-offers/{id}/schedules', [ScheduleController::class, 'publicList']);
 Route::get('/diving-offers/{id}/reviews',  [ReviewController::class, 'publicList']);
 
-// 你可以在這裡繼續新增 API 路由
-Route::post('/testpost', function () {
-    $data = request()->all(); // 取得所有POST資料（array）
-    return response()->json([
-        'data' => $data,
-    ]);
-});
-
 // 會員註冊／登入
 Route::post('/member/register', [AuthController::class, 'registerMember']);
 Route::post('/member/login', [AuthController::class, 'loginMember']);
@@ -153,6 +144,15 @@ Route::middleware('auth:sanctum')->prefix('notifications')->group(function () {
     Route::delete('/{id}',      [NotificationController::class, 'destroy']);
 });
 
+// 即時訊息（Member + Provider 共用，依 booking 參與方驗證）
+Route::middleware('auth:sanctum')->group(function () {
+    // unread-counts 必須在 {booking} 之前，否則會被 route model binding 吃掉
+    Route::get('/bookings/messages/unread-counts',   [BookingMessageController::class, 'unreadCounts']);
+    Route::get('/bookings/{booking}/messages',       [BookingMessageController::class, 'index']);
+    Route::post('/bookings/{booking}/messages',      [BookingMessageController::class, 'store']);
+    Route::post('/bookings/{booking}/messages/read', [BookingMessageController::class, 'markRead']);
+});
+
 // 需要認證的通用路由
 Route::middleware('auth:sanctum')->group(function () {
     Route::post('/logout', [AuthController::class, 'logout']);

routes/channels.php

@@ -0,0 +1,10 @@
+<?php
+
+use App\Broadcasting\BookingPresenceChannel;
+use Illuminate\Support\Facades\Broadcast;
+
+Broadcast::channel('App.Models.User.{id}', function ($user, $id) {
+    return (int) $user->id === (int) $id;
+});
+
+Broadcast::channel('booking.{booking}', BookingPresenceChannel::class);