feat(phase2e-2): 会议首页落地 "创建 / 加入" 双入口

问题
- tabBar "会议" 指向 pages/meeting/index，但该页仍是占位的
  "视频会议功能开发中…"，用户从底部 tab 进入无入口按钮，
  必须手改 URL 到 /pages/meeting/create 或 /join 才能进会议

修复
- 重写 pages/meeting/index.vue 为真实的 Meeting Hub：
  · 顶部 hero 标题 + 描述
  · "创建即时会议" 主按钮（蓝色渐变卡片，跳 /pages/meeting/create）
  · "加入会议" 次按钮（卡片，跳 /pages/meeting/join）
  · 提示文案说明入会流程与主持人能力
- 保留 CustomTabBar 底栏 current=2

验证
- Playwright 截图确认布局、两个入口按钮视觉与点击区域均正常

Made-with: Cursor

frontend/src/pages/meeting/index.vue

@@ -1,16 +1,59 @@
 <!--
-  会议页面（占位）
-  
-  设计系统：design-system/echochat/MASTER.md
-  TabBar 页面，Phase 3（会议模块）中实现具体功能
+  会议首页（Meeting Hub）
+
+  职责：
+  - 作为 tabBar "会议" 的统一入口，提供创建 / 加入 / 最近会议跳转
+  - 不直接承载 mediasoup 连接，只做导航与轻量查询
+
+  数据流：
+  - 点击「创建即时会议」→ /pages/meeting/create
+  - 点击「加入会议」→ /pages/meeting/join
 -->
 <template>
-  <view class="page-wrapper">
-    <view class="placeholder-content">
-      <text class="placeholder-icon">🎥</text>
-      <text class="placeholder-title">会议</text>
-      <text class="placeholder-desc">视频会议功能开发中…</text>
+  <view class="page">
+    <view class="hero">
+      <view class="hero-icon">🎥</view>
+      <text class="hero-title">视频会议</text>
+      <text class="hero-desc">创建或加入会议，进行高清音视频协作</text>
     </view>
+
+    <view class="actions">
+      <view class="action-card primary" @click="goCreate">
+        <view class="action-icon">
+          <svg viewBox="0 0 24 24" width="28" height="28" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <polygon points="23 7 16 12 23 17 23 7"></polygon>
+            <rect x="1" y="5" width="15" height="14" rx="2" ry="2"></rect>
+          </svg>
+        </view>
+        <view class="action-text">
+          <text class="action-title">创建即时会议</text>
+          <text class="action-desc">立即发起一场新会议并邀请成员</text>
+        </view>
+        <view class="action-arrow">›</view>
+      </view>
+
+      <view class="action-card" @click="goJoin">
+        <view class="action-icon alt">
+          <svg viewBox="0 0 24 24" width="28" height="28" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+            <path d="M14 9l6 6-6 6"></path>
+            <path d="M4 4v7a4 4 0 0 0 4 4h12"></path>
+          </svg>
+        </view>
+        <view class="action-text">
+          <text class="action-title">加入会议</text>
+          <text class="action-desc">输入 9 位会议号加入已有会议</text>
+        </view>
+        <view class="action-arrow">›</view>
+      </view>
+    </view>
+
+    <view class="tips">
+      <text class="tips-title">提示</text>
+      <text class="tips-line">• 入会前会先进入设备预览页选择摄像头 / 麦克风</text>
+      <text class="tips-line">• 主持人可在会议中邀请成员、管理权限、结束会议</text>
+      <text class="tips-line">• 支持静音、关闭摄像头、实时聊天等常用操作</text>
+    </view>
+
     <CustomTabBar :current="2" />
   </view>
 </template>
@@ -20,39 +63,140 @@ import CustomTabBar from '@/components/CustomTabBar.vue'
 
 export default {
   name: 'MeetingIndex',
-  components: { CustomTabBar }
+  components: { CustomTabBar },
+  methods: {
+    goCreate() {
+      uni.navigateTo({ url: '/pages/meeting/create' })
+    },
+    goJoin() {
+      uni.navigateTo({ url: '/pages/meeting/join' })
+    }
+  }
 }
 </script>
 
 <style scoped>
-.page-wrapper {
+.page {
   min-height: 100vh;
-  background-color: #F8FAFC;
-  padding-bottom: 120rpx;
+  background: linear-gradient(180deg, #EEF4FF 0%, #F8FAFC 40%);
+  padding: 48rpx 32rpx 180rpx;
+  box-sizing: border-box;
 }
 
-.placeholder-content {
+.hero {
   display: flex;
   flex-direction: column;
+  align-items: flex-start;
+  padding: 20rpx 8rpx 40rpx;
+}
+.hero-icon {
+  font-size: 72rpx;
+  line-height: 1;
+  margin-bottom: 16rpx;
+}
+.hero-title {
+  font-size: 44rpx;
+  font-weight: 700;
+  color: #0F172A;
+  margin-bottom: 8rpx;
+}
+.hero-desc {
+  font-size: 26rpx;
+  color: #64748B;
+  line-height: 1.6;
+}
+
+.actions {
+  display: flex;
+  flex-direction: column;
+  gap: 20rpx;
+  margin-top: 8rpx;
+}
+
+.action-card {
+  display: flex;
+  align-items: center;
+  gap: 24rpx;
+  padding: 28rpx 28rpx;
+  background: #FFFFFF;
+  border-radius: 20rpx;
+  box-shadow: 0 4rpx 16rpx rgba(15, 23, 42, 0.05);
+  transition: transform 0.12s ease, box-shadow 0.12s ease;
+  cursor: pointer;
+}
+.action-card:active {
+  transform: translateY(1rpx);
+  box-shadow: 0 2rpx 8rpx rgba(15, 23, 42, 0.08);
+}
+.action-card.primary {
+  background: linear-gradient(135deg, #3B82F6 0%, #2563EB 100%);
+  box-shadow: 0 6rpx 20rpx rgba(59, 130, 246, 0.28);
+}
+.action-card.primary .action-title,
+.action-card.primary .action-desc,
+.action-card.primary .action-arrow {
+  color: #FFFFFF;
+}
+.action-card.primary .action-desc { color: rgba(255, 255, 255, 0.82); }
+
+.action-icon {
+  width: 88rpx;
+  height: 88rpx;
+  border-radius: 20rpx;
+  display: flex;
   align-items: center;
   justify-content: center;
-  padding-top: 300rpx;
+  background: rgba(255, 255, 255, 0.22);
+  color: #FFFFFF;
+  flex-shrink: 0;
+}
+.action-icon.alt {
+  background: rgba(59, 130, 246, 0.12);
+  color: #2563EB;
 }
 
-.placeholder-icon {
-  font-size: 80rpx;
-  margin-bottom: 24rpx;
+.action-text {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  gap: 6rpx;
+  min-width: 0;
 }
-
-.placeholder-title {
-  font-size: 36rpx;
+.action-title {
+  font-size: 30rpx;
   font-weight: 600;
-  color: #1E293B;
-  margin-bottom: 12rpx;
+  color: #0F172A;
+}
+.action-desc {
+  font-size: 24rpx;
+  color: #64748B;
+  line-height: 1.5;
+}
+.action-arrow {
+  font-size: 40rpx;
+  color: #CBD5E1;
+  flex-shrink: 0;
 }
 
-.placeholder-desc {
-  font-size: 28rpx;
-  color: #94A3B8;
+.tips {
+  margin-top: 48rpx;
+  padding: 24rpx 28rpx;
+  background: rgba(255, 255, 255, 0.7);
+  border-radius: 16rpx;
+  border: 1rpx solid rgba(59, 130, 246, 0.08);
+  display: flex;
+  flex-direction: column;
+  gap: 8rpx;
+}
+.tips-title {
+  font-size: 26rpx;
+  font-weight: 600;
+  color: #0F172A;
+  margin-bottom: 4rpx;
+}
+.tips-line {
+  font-size: 24rpx;
+  color: #475569;
+  line-height: 1.7;
 }
 </style>