feat(phase2e-2): 前端创建/加入/设备预览 3 页落地（Task 10）

页面
- pages/meeting/create.vue：创建表单，标题(默认"{昵称}的会议"/40 字限制) + 密码(4-16 位)
  + 入会静音开关 + 允许聊天开关。提交时表单暂存到 store.draftCreatePayload，跳 preview 页
- pages/meeting/join.vue：会议号输入（9 位纯数字/带连字符均可，自动格式化 XXX-XXX-XXX）
  + 可选密码。支持 URL query code/password 回填（邀请链接一键入会入口）
- pages/meeting/preview.vue：设备预览页
  - navigator.mediaDevices.enumerateDevices() 列出摄像头/麦克风/扬声器
  - getUserMedia({video,audio}) 本地画面预览（用原生 <video> 避开 uni-input 对 srcObject 的限制）
  - AudioContext.AnalyserNode 以 rAF 采样 RMS，渲染渐变音量条
  - 显示名输入 + 入会默认开麦/开摄像头开关
  - 权限被拒/浏览器不支持 WebRTC 时给清晰错误提示
  - 离开页时释放 preview stream 与 AudioContext，避免占用摄像头

Store 扩展（meeting.js）
- 新增 state：draftCreatePayload（create→preview 暂存） + devicePreview（设备选择结果）
- createAndEnter(payload, mediaPrefs?) / joinAndEnter(code, password, mediaPrefs?) 新增
  可选 mediaPrefs 参数：{ startAudio, startVideo, audioDeviceId, videoDeviceId }
- _afterJoined 内按 mediaPrefs 入会后自动 startLocalAudio/Video（失败仅告警不阻断）
- startLocalAudio/Video 支持可选 deviceId，映射到 getUserMedia 的 deviceId.exact 约束

路由
- pages.json 注册 create/join/preview 3 条路由（均非 TabBar 页，从 URL 或后续入口跳入）

临时占位
- preview 页加入成功后暂时 redirectTo 到 debug.vue（Task 11 room 页待落地时改为 /pages/meeting/room）

Playwright 验证（真实 macOS 设备）
- create → preview：表单 "新昵称的会议" 正确携带到 preview 页
- preview 页：FaceTime 摄像头 + MacBook Pro 麦克风枚举成功，video readyState=4，音量条工作正常
- 点"加入会议"：createAndEnter 成功，debug 页显示 localState=connected，主持人=是
  mediaPrefs 生效——麦克风/摄像头按钮显示"关闭麦克风/关闭摄像头"说明自动推流成功
- join 页：URL ?code=123-456-789&password=secret 正确预填，"下一步" 按钮启用

Made-with: Cursor

frontend/src/pages.json

@@ -148,6 +148,24 @@
 				"navigationBarTitleText": "会议调试（Task 9）"
 			}
 		},
+		{
+			"path": "pages/meeting/create",
+			"style": {
+				"navigationBarTitleText": "创建会议"
+			}
+		},
+		{
+			"path": "pages/meeting/join",
+			"style": {
+				"navigationBarTitleText": "加入会议"
+			}
+		},
+		{
+			"path": "pages/meeting/preview",
+			"style": {
+				"navigationBarTitleText": "设备预览"
+			}
+		},
 		{
 			"path": "pages/notify/index",
 			"style": {

frontend/src/pages/meeting/create.vue

@@ -0,0 +1,187 @@
+<!--
+  创建会议表单页（Task 10）
+
+  数据流：
+    用户在本页填写 title/password/开关 → 点击"下一步"
+    → 保存表单到 meetingStore.draftCreatePayload
+    → uni.navigateTo('/pages/meeting/preview?mode=create')
+    → 在预览页选定设备后真正调用 createAndEnter
+
+  设计依据：
+  - Phase 2e-2 设计 §8.1 路由表 + D04 决策（入会前强制经过设备预览页）
+  - 本页不调用任何会议 API，无副作用；取消即返回
+-->
+<template>
+  <view class="page">
+    <view class="container">
+      <text class="title">创建会议</text>
+      <text class="subtitle">填写会议基本信息，下一步设置摄像头与麦克风</text>
+
+      <view class="card">
+        <view class="field">
+          <text class="label">会议标题 <text class="required">*</text></text>
+          <input
+            v-model="form.title"
+            class="input"
+            placeholder="例如：周会同步（限 40 字）"
+            maxlength="40"
+          />
+          <text class="hint" v-if="titleError">{{ titleError }}</text>
+        </view>
+
+        <view class="field">
+          <text class="label">会议密码（可选）</text>
+          <input
+            v-model="form.password"
+            class="input"
+            placeholder="留空表示无密码；4-16 位数字/字母"
+            maxlength="16"
+          />
+          <text class="hint" v-if="passwordError">{{ passwordError }}</text>
+        </view>
+
+        <view class="field switch-row">
+          <view class="switch-label">
+            <text class="label">入会默认静音</text>
+            <text class="desc">新成员加入时麦克风默认关闭</text>
+          </view>
+          <switch :checked="form.enter_muted" @change="onToggleMuted" color="#3B82F6" />
+        </view>
+
+        <view class="field switch-row">
+          <view class="switch-label">
+            <text class="label">允许会议内聊天</text>
+            <text class="desc">关闭后成员不能发送聊天消息</text>
+          </view>
+          <switch :checked="form.allow_chat" @change="onToggleChat" color="#3B82F6" />
+        </view>
+      </view>
+
+      <view class="actions">
+        <button class="btn btn-secondary" @click="onCancel">取消</button>
+        <button class="btn btn-primary" :disabled="!isFormValid" @click="onNext">下一步：设备预览</button>
+      </view>
+    </view>
+  </view>
+</template>
+
+<script setup>
+import { reactive, computed } from 'vue'
+import { useMeetingStore } from '@/store/meeting'
+import { useUserStore } from '@/store/user'
+
+const meetingStore = useMeetingStore()
+const userStore = useUserStore()
+
+const defaultTitle = () => {
+  const name = userStore.userInfo?.nickname || userStore.userInfo?.username || '我'
+  return `${name}的会议`
+}
+
+const form = reactive({
+  title: defaultTitle(),
+  password: '',
+  enter_muted: false,
+  allow_chat: true
+})
+
+const titleError = computed(() => {
+  const t = form.title.trim()
+  if (!t) return '会议标题不能为空'
+  if (t.length > 40) return '会议标题不能超过 40 字'
+  return ''
+})
+
+const passwordError = computed(() => {
+  const p = form.password
+  if (!p) return ''
+  if (p.length < 4 || p.length > 16) return '密码长度需为 4-16 位'
+  if (!/^[A-Za-z0-9]+$/.test(p)) return '密码仅支持数字和英文字母'
+  return ''
+})
+
+const isFormValid = computed(() => !titleError.value && !passwordError.value)
+
+const onToggleMuted = (e) => { form.enter_muted = e.detail.value }
+const onToggleChat = (e) => { form.allow_chat = e.detail.value }
+
+const onNext = () => {
+  if (!isFormValid.value) return
+  meetingStore.draftCreatePayload = {
+    title: form.title.trim(),
+    password: form.password || undefined,
+    enter_muted: form.enter_muted,
+    allow_chat: form.allow_chat
+  }
+  uni.navigateTo({ url: '/pages/meeting/preview?mode=create' })
+}
+
+const onCancel = () => {
+  uni.navigateBack()
+}
+</script>
+
+<style scoped>
+.page { min-height: 100vh; background: #F8FAFC; padding: 24rpx; }
+.container { max-width: 680rpx; margin: 0 auto; }
+.title { font-size: 40rpx; font-weight: 600; color: #0F172A; display: block; margin: 24rpx 0 8rpx; }
+.subtitle { font-size: 26rpx; color: #64748B; display: block; margin-bottom: 32rpx; }
+
+.card {
+  background: #FFFFFF;
+  border-radius: 16rpx;
+  padding: 32rpx;
+  box-shadow: 0 2rpx 8rpx rgba(15, 23, 42, 0.04);
+}
+
+.field { margin-bottom: 28rpx; }
+.field:last-child { margin-bottom: 0; }
+.label { font-size: 28rpx; color: #1E293B; font-weight: 500; display: block; margin-bottom: 12rpx; }
+.required { color: #EF4444; font-weight: 600; }
+.desc { font-size: 24rpx; color: #94A3B8; display: block; margin-top: 4rpx; }
+.hint { font-size: 22rpx; color: #EF4444; display: block; margin-top: 8rpx; }
+
+.input {
+  width: 100%;
+  padding: 20rpx 24rpx;
+  background: #F1F5F9;
+  border-radius: 12rpx;
+  font-size: 28rpx;
+  color: #0F172A;
+  border: 1px solid transparent;
+}
+.input:focus { border-color: #3B82F6; background: #FFFFFF; }
+
+.switch-row {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+}
+.switch-label { flex: 1; }
+
+.actions {
+  display: flex;
+  gap: 24rpx;
+  margin-top: 40rpx;
+}
+.btn {
+  flex: 1;
+  padding: 24rpx 0;
+  border-radius: 12rpx;
+  font-size: 30rpx;
+  font-weight: 500;
+  border: none;
+}
+.btn-secondary {
+  background: #F1F5F9;
+  color: #475569;
+}
+.btn-primary {
+  background: #3B82F6;
+  color: #FFFFFF;
+}
+.btn-primary[disabled] {
+  background: #BFDBFE;
+  color: #FFFFFF;
+}
+</style>

frontend/src/pages/meeting/join.vue

@@ -0,0 +1,168 @@
+<!--
+  加入会议表单页（Task 10）
+
+  数据流：
+    用户输入会议号（可粘贴带 / 不带连字符的 9 位数字）+ 可选密码 → 点击"下一步"
+    → uni.navigateTo('/pages/meeting/preview?mode=join&code=XXX-XXX-XXX&password=xxx')
+    → 预览页选定设备后真正调用 joinAndEnter
+
+  邀请链接支持：
+  - URL 参数 code=XXX-XXX-XXX（必传时直接回填）
+  - URL 参数 password=xxx（可选，从邀请短链来）
+  - 参考设计 §2.2.1：邀请链接形如 /#/pages/meeting/join?code=XXX-XXX-XXX
+-->
+<template>
+  <view class="page">
+    <view class="container">
+      <text class="title">加入会议</text>
+      <text class="subtitle">输入主持人分享的 9 位会议号，下一步选择设备</text>
+
+      <view class="card">
+        <view class="field">
+          <text class="label">会议号 <text class="required">*</text></text>
+          <input
+            v-model="rawCodeInput"
+            class="input code-input"
+            placeholder="XXX-XXX-XXX"
+            maxlength="11"
+            @input="onCodeInput"
+          />
+          <text class="hint" v-if="codeError">{{ codeError }}</text>
+          <text class="hint neutral" v-else-if="formattedCode">已识别：{{ formattedCode }}</text>
+        </view>
+
+        <view class="field">
+          <text class="label">会议密码（如有）</text>
+          <input
+            v-model="form.password"
+            class="input"
+            placeholder="若会议设置了密码请填写"
+            maxlength="16"
+          />
+        </view>
+      </view>
+
+      <view class="actions">
+        <button class="btn btn-secondary" @click="onCancel">取消</button>
+        <button class="btn btn-primary" :disabled="!isFormValid" @click="onNext">下一步：设备预览</button>
+      </view>
+    </view>
+  </view>
+</template>
+
+<script setup>
+import { ref, reactive, computed } from 'vue'
+import { onLoad } from '@dcloudio/uni-app'
+
+const rawCodeInput = ref('')
+const form = reactive({ password: '' })
+
+/** 去掉所有非数字字符，截至 9 位 */
+const digitsOf = (s) => (s || '').replace(/\D/g, '').slice(0, 9)
+
+/** 把 9 位数字格式化为 XXX-XXX-XXX（不足 9 位时按实际位数插连字符） */
+const formatCode = (digits) => {
+  if (digits.length <= 3) return digits
+  if (digits.length <= 6) return `${digits.slice(0, 3)}-${digits.slice(3)}`
+  return `${digits.slice(0, 3)}-${digits.slice(3, 6)}-${digits.slice(6)}`
+}
+
+const formattedCode = computed(() => {
+  const d = digitsOf(rawCodeInput.value)
+  return d.length === 9 ? formatCode(d) : ''
+})
+
+const codeError = computed(() => {
+  const d = digitsOf(rawCodeInput.value)
+  if (d.length === 0) return ''
+  if (d.length < 9) return `还差 ${9 - d.length} 位`
+  return ''
+})
+
+const isFormValid = computed(() => digitsOf(rawCodeInput.value).length === 9)
+
+const onCodeInput = (e) => {
+  // 同时兼容 uni-app 事件（e.detail.value）与原生 input 事件（e.target.value），自动化测试友好
+  const raw = e?.detail?.value ?? e?.target?.value ?? rawCodeInput.value
+  const d = digitsOf(raw)
+  rawCodeInput.value = formatCode(d)
+}
+
+onLoad((query) => {
+  if (query?.code) {
+    const d = digitsOf(query.code)
+    if (d.length === 9) rawCodeInput.value = formatCode(d)
+  }
+  if (query?.password) {
+    form.password = String(query.password)
+  }
+})
+
+const onNext = () => {
+  if (!isFormValid.value) return
+  const code = formattedCode.value
+  const passwordQuery = form.password ? `&password=${encodeURIComponent(form.password)}` : ''
+  uni.navigateTo({
+    url: `/pages/meeting/preview?mode=join&code=${code}${passwordQuery}`
+  })
+}
+
+const onCancel = () => {
+  uni.navigateBack()
+}
+</script>
+
+<style scoped>
+.page { min-height: 100vh; background: #F8FAFC; padding: 24rpx; }
+.container { max-width: 680rpx; margin: 0 auto; }
+.title { font-size: 40rpx; font-weight: 600; color: #0F172A; display: block; margin: 24rpx 0 8rpx; }
+.subtitle { font-size: 26rpx; color: #64748B; display: block; margin-bottom: 32rpx; }
+
+.card {
+  background: #FFFFFF;
+  border-radius: 16rpx;
+  padding: 32rpx;
+  box-shadow: 0 2rpx 8rpx rgba(15, 23, 42, 0.04);
+}
+
+.field { margin-bottom: 28rpx; }
+.field:last-child { margin-bottom: 0; }
+.label { font-size: 28rpx; color: #1E293B; font-weight: 500; display: block; margin-bottom: 12rpx; }
+.required { color: #EF4444; font-weight: 600; }
+.hint { font-size: 22rpx; color: #EF4444; display: block; margin-top: 8rpx; }
+.hint.neutral { color: #10B981; }
+
+.input {
+  width: 100%;
+  padding: 20rpx 24rpx;
+  background: #F1F5F9;
+  border-radius: 12rpx;
+  font-size: 28rpx;
+  color: #0F172A;
+  border: 1px solid transparent;
+}
+.input:focus { border-color: #3B82F6; background: #FFFFFF; }
+.code-input {
+  font-size: 36rpx;
+  letter-spacing: 4rpx;
+  text-align: center;
+  font-variant-numeric: tabular-nums;
+}
+
+.actions {
+  display: flex;
+  gap: 24rpx;
+  margin-top: 40rpx;
+}
+.btn {
+  flex: 1;
+  padding: 24rpx 0;
+  border-radius: 12rpx;
+  font-size: 30rpx;
+  font-weight: 500;
+  border: none;
+}
+.btn-secondary { background: #F1F5F9; color: #475569; }
+.btn-primary { background: #3B82F6; color: #FFFFFF; }
+.btn-primary[disabled] { background: #BFDBFE; color: #FFFFFF; }
+</style>

frontend/src/pages/meeting/preview.vue

@@ -0,0 +1,495 @@
+<!--
+  设备预览页（Task 10）
+
+  来自：
+  - /pages/meeting/create（mode=create）→ 读 meetingStore.draftCreatePayload 调 createAndEnter
+  - /pages/meeting/join（mode=join&code=...&password=...）→ 调 joinAndEnter
+
+  核心能力：
+  - navigator.mediaDevices.enumerateDevices() 列出摄像头/麦克风/扬声器
+  - getUserMedia({ audio, video }) 本地画面 + 音频轨预览
+  - AudioContext + AnalyserNode 实时音量条（20Hz 采样）
+  - 「入会默认开麦/摄像头」两个开关写入 mediaPrefs
+  - 兜底：权限被拒 / 浏览器不支持 WebRTC 时给明确错误提示
+
+  入会成功后（Task 11 room 页未就绪期间）：uni.redirectTo 到会议调试页 debug.vue 作为会议室占位。
+  TODO（Task 11 落地后）：改为 uni.redirectTo '/pages/meeting/room?code=xxx'
+-->
+<template>
+  <view class="page">
+    <view class="container">
+      <text class="title">设备预览</text>
+      <text class="subtitle">{{ modeLabel }}，确认设备和显示名称后加入会议</text>
+
+      <view class="content">
+        <view class="preview-box">
+          <view ref="videoBox" class="video-slot"></view>
+          <view class="preview-footer">
+            <view class="volume-wrap">
+              <text class="volume-label">麦克风音量</text>
+              <view class="volume-bar"><view class="volume-fill" :style="{ width: volumePercent + '%' }"></view></view>
+            </view>
+            <text v-if="permissionError" class="error">{{ permissionError }}</text>
+          </view>
+        </view>
+
+        <view class="controls card">
+          <view class="field">
+            <text class="label">摄像头</text>
+            <picker
+              :value="videoPickerIndex"
+              :range="videoDeviceLabels"
+              :disabled="!hasPermission || videoDevices.length === 0"
+              @change="onVideoChange"
+            >
+              <view class="picker">{{ videoDeviceLabels[videoPickerIndex] || '未检测到摄像头' }}</view>
+            </picker>
+          </view>
+
+          <view class="field">
+            <text class="label">麦克风</text>
+            <picker
+              :value="audioPickerIndex"
+              :range="audioDeviceLabels"
+              :disabled="!hasPermission || audioDevices.length === 0"
+              @change="onAudioChange"
+            >
+              <view class="picker">{{ audioDeviceLabels[audioPickerIndex] || '未检测到麦克风' }}</view>
+            </picker>
+          </view>
+
+          <view class="field" v-if="speakerDevices.length > 0">
+            <text class="label">扬声器</text>
+            <picker
+              :value="speakerPickerIndex"
+              :range="speakerDeviceLabels"
+              @change="onSpeakerChange"
+            >
+              <view class="picker">{{ speakerDeviceLabels[speakerPickerIndex] || '系统默认' }}</view>
+            </picker>
+          </view>
+
+          <view class="field">
+            <text class="label">显示名称</text>
+            <input v-model="displayName" class="input" placeholder="会议中显示的名字" maxlength="20" />
+          </view>
+
+          <view class="field switch-row">
+            <view class="switch-label">
+              <text class="label">入会默认开启摄像头</text>
+            </view>
+            <switch :checked="mediaPrefs.startVideo" @change="onToggleVideoDefault" color="#3B82F6" />
+          </view>
+
+          <view class="field switch-row">
+            <view class="switch-label">
+              <text class="label">入会默认开启麦克风</text>
+            </view>
+            <switch :checked="mediaPrefs.startAudio" @change="onToggleAudioDefault" color="#3B82F6" />
+          </view>
+        </view>
+      </view>
+
+      <view class="actions">
+        <button class="btn btn-secondary" :disabled="joining" @click="onCancel">上一步</button>
+        <button class="btn btn-primary" :disabled="joining || !canJoin" @click="onJoin">
+          {{ joining ? '加入中…' : '加入会议' }}
+        </button>
+      </view>
+    </view>
+  </view>
+</template>
+
+<script setup>
+import { ref, reactive, computed, onBeforeUnmount, nextTick } from 'vue'
+import { onLoad } from '@dcloudio/uni-app'
+import { useMeetingStore } from '@/store/meeting'
+import { useUserStore } from '@/store/user'
+
+const meetingStore = useMeetingStore()
+const userStore = useUserStore()
+
+const mode = ref('create')
+const joinCode = ref('')
+const joinPassword = ref('')
+
+const modeLabel = computed(() => mode.value === 'create' ? '即将创建新会议' : `即将加入会议 ${joinCode.value}`)
+
+const videoBox = ref(null)
+let previewStream = null
+let audioContext = null
+let analyser = null
+let volumeRafId = null
+
+const hasPermission = ref(false)
+const permissionError = ref('')
+const joining = ref(false)
+
+const videoDevices = ref([])
+const audioDevices = ref([])
+const speakerDevices = ref([])
+
+const selectedVideoId = ref('')
+const selectedAudioId = ref('')
+const selectedSpeakerId = ref('')
+
+const videoDeviceLabels = computed(() => videoDevices.value.map((d, i) => d.label || `摄像头 ${i + 1}`))
+const audioDeviceLabels = computed(() => audioDevices.value.map((d, i) => d.label || `麦克风 ${i + 1}`))
+const speakerDeviceLabels = computed(() => speakerDevices.value.map((d, i) => d.label || `扬声器 ${i + 1}`))
+
+const videoPickerIndex = computed(() => {
+  const i = videoDevices.value.findIndex(d => d.deviceId === selectedVideoId.value)
+  return i < 0 ? 0 : i
+})
+const audioPickerIndex = computed(() => {
+  const i = audioDevices.value.findIndex(d => d.deviceId === selectedAudioId.value)
+  return i < 0 ? 0 : i
+})
+const speakerPickerIndex = computed(() => {
+  const i = speakerDevices.value.findIndex(d => d.deviceId === selectedSpeakerId.value)
+  return i < 0 ? 0 : i
+})
+
+const displayName = ref(userStore.userInfo?.nickname || userStore.userInfo?.username || '')
+const mediaPrefs = reactive({
+  startAudio: true,
+  startVideo: true
+})
+
+const volumePercent = ref(0)
+
+const canJoin = computed(() => {
+  if (mode.value === 'join' && !joinCode.value) return false
+  return true
+})
+
+// ==================== 设备 / 预览流 ====================
+
+const stopPreviewStream = () => {
+  if (previewStream) {
+    previewStream.getTracks().forEach(t => { try { t.stop() } catch {} })
+    previewStream = null
+  }
+}
+
+const stopAudioMeter = () => {
+  if (volumeRafId) {
+    cancelAnimationFrame(volumeRafId)
+    volumeRafId = null
+  }
+  if (audioContext) {
+    try { audioContext.close() } catch {}
+    audioContext = null
+    analyser = null
+  }
+  volumePercent.value = 0
+}
+
+/** 基于当前已选 deviceId 启动预览（无 ID 则首次调用由浏览器分配默认设备） */
+const startPreview = async () => {
+  // #ifdef H5
+  if (!navigator.mediaDevices || !navigator.mediaDevices.getUserMedia) {
+    permissionError.value = '当前浏览器不支持音视频预览（需 HTTPS + WebRTC）'
+    return
+  }
+  stopPreviewStream()
+  stopAudioMeter()
+  try {
+    const constraints = {
+      audio: selectedAudioId.value ? { deviceId: { exact: selectedAudioId.value } } : true,
+      video: selectedVideoId.value
+        ? { deviceId: { exact: selectedVideoId.value }, width: 640, height: 480 }
+        : { width: 640, height: 480 }
+    }
+    previewStream = await navigator.mediaDevices.getUserMedia(constraints)
+    hasPermission.value = true
+    permissionError.value = ''
+    await nextTick()
+    mountPreviewVideo()
+    startAudioMeter(previewStream)
+  } catch (err) {
+    hasPermission.value = false
+    permissionError.value = err?.name === 'NotAllowedError'
+      ? '已拒绝摄像头/麦克风权限，请在浏览器地址栏左侧恢复权限后重试'
+      : `无法访问音视频设备：${err?.message || err}`
+    console.warn('[Preview] getUserMedia 失败', err)
+  }
+  // #endif
+}
+
+const mountPreviewVideo = () => {
+  // #ifdef H5
+  const parent = resolveDom(videoBox.value)
+  if (!parent || !previewStream) return
+  let videoEl = parent.querySelector(':scope > video')
+  if (!videoEl) {
+    videoEl = document.createElement('video')
+    videoEl.autoplay = true
+    videoEl.playsInline = true
+    videoEl.muted = true // 预览时本地回声静音
+    videoEl.style.width = '100%'
+    videoEl.style.height = '100%'
+    videoEl.style.objectFit = 'cover'
+    videoEl.style.background = '#000'
+    videoEl.style.borderRadius = '12rpx'
+    parent.appendChild(videoEl)
+  }
+  videoEl.srcObject = previewStream
+  // #endif
+}
+
+const resolveDom = (refValue) => {
+  if (!refValue) return null
+  // #ifdef H5
+  if (refValue instanceof HTMLElement) return refValue
+  if (refValue.$el) return refValue.$el
+  if (refValue.exposed && refValue.exposed.$el) return refValue.exposed.$el
+  // #endif
+  return null
+}
+
+/** 用 AudioContext.AnalyserNode 采样 RMS，换算成 0-100 的音量条 */
+const startAudioMeter = (stream) => {
+  // #ifdef H5
+  const audioTrack = stream.getAudioTracks()[0]
+  if (!audioTrack) return
+  try {
+    const AC = window.AudioContext || window.webkitAudioContext
+    if (!AC) return
+    audioContext = new AC()
+    const source = audioContext.createMediaStreamSource(new MediaStream([audioTrack]))
+    analyser = audioContext.createAnalyser()
+    analyser.fftSize = 1024
+    source.connect(analyser)
+    const data = new Uint8Array(analyser.fftSize)
+    const loop = () => {
+      if (!analyser) return
+      analyser.getByteTimeDomainData(data)
+      // RMS：((sample-128)/128) 的平方平均
+      let sum = 0
+      for (let i = 0; i < data.length; i++) {
+        const v = (data[i] - 128) / 128
+        sum += v * v
+      }
+      const rms = Math.sqrt(sum / data.length)
+      // 经验映射：放大 1.6 倍，截顶 100
+      volumePercent.value = Math.min(100, Math.round(rms * 160))
+      volumeRafId = requestAnimationFrame(loop)
+    }
+    loop()
+  } catch (err) {
+    console.warn('[Preview] AudioMeter 失败', err)
+  }
+  // #endif
+}
+
+const loadDevices = async () => {
+  // #ifdef H5
+  if (!navigator.mediaDevices?.enumerateDevices) return
+  const list = await navigator.mediaDevices.enumerateDevices()
+  videoDevices.value = list.filter(d => d.kind === 'videoinput')
+  audioDevices.value = list.filter(d => d.kind === 'audioinput')
+  speakerDevices.value = list.filter(d => d.kind === 'audiooutput')
+  // 有权限后 label 才会返回，没默认选中时自动选第一个
+  if (!selectedVideoId.value && videoDevices.value[0]) selectedVideoId.value = videoDevices.value[0].deviceId
+  if (!selectedAudioId.value && audioDevices.value[0]) selectedAudioId.value = audioDevices.value[0].deviceId
+  if (!selectedSpeakerId.value && speakerDevices.value[0]) selectedSpeakerId.value = speakerDevices.value[0].deviceId
+  // #endif
+}
+
+// ==================== 事件 ====================
+
+const onVideoChange = (e) => {
+  const idx = Number(e.detail.value)
+  const d = videoDevices.value[idx]
+  if (!d) return
+  selectedVideoId.value = d.deviceId
+  startPreview()
+}
+const onAudioChange = (e) => {
+  const idx = Number(e.detail.value)
+  const d = audioDevices.value[idx]
+  if (!d) return
+  selectedAudioId.value = d.deviceId
+  startPreview()
+}
+const onSpeakerChange = (e) => {
+  const idx = Number(e.detail.value)
+  const d = speakerDevices.value[idx]
+  if (!d) return
+  selectedSpeakerId.value = d.deviceId
+}
+
+const onToggleVideoDefault = (e) => { mediaPrefs.startVideo = e.detail.value }
+const onToggleAudioDefault = (e) => { mediaPrefs.startAudio = e.detail.value }
+
+const onCancel = () => {
+  uni.navigateBack()
+}
+
+const onJoin = async () => {
+  if (joining.value || !canJoin.value) return
+  joining.value = true
+
+  meetingStore.devicePreview = {
+    audioDeviceId: selectedAudioId.value,
+    videoDeviceId: selectedVideoId.value,
+    speakerDeviceId: selectedSpeakerId.value,
+    displayName: displayName.value,
+    startAudio: mediaPrefs.startAudio,
+    startVideo: mediaPrefs.startVideo
+  }
+
+  // 释放预览流，避免与 mediasoup produce 争用摄像头（浏览器单轨互斥）
+  stopPreviewStream()
+  stopAudioMeter()
+
+  const prefs = {
+    startAudio: mediaPrefs.startAudio,
+    startVideo: mediaPrefs.startVideo,
+    audioDeviceId: selectedAudioId.value,
+    videoDeviceId: selectedVideoId.value
+  }
+
+  try {
+    if (mode.value === 'create') {
+      const payload = meetingStore.draftCreatePayload
+      if (!payload) {
+        throw new Error('未找到创建会议的表单草稿，请返回创建页重新填写')
+      }
+      await meetingStore.createAndEnter(payload, prefs)
+      meetingStore.draftCreatePayload = null
+    } else {
+      await meetingStore.joinAndEnter(joinCode.value, joinPassword.value, prefs)
+    }
+    // Task 11 会议室页尚未落地，临时跳转 debug.vue 作为会议室占位
+    uni.redirectTo({ url: '/pages/meeting/debug' })
+  } catch (err) {
+    const msg = err?.message || JSON.stringify(err)
+    uni.showToast({ title: `加入失败：${msg}`, icon: 'none', duration: 3500 })
+    console.error('[Preview] 加入会议失败', err)
+  } finally {
+    joining.value = false
+  }
+}
+
+// ==================== 生命周期 ====================
+
+onLoad(async (query) => {
+  mode.value = query?.mode === 'join' ? 'join' : 'create'
+  joinCode.value = query?.code || ''
+  joinPassword.value = query?.password ? decodeURIComponent(query.password) : ''
+
+  // 先请求权限并预览，默认拿到第一个设备
+  await startPreview()
+  // 权限到手后枚举设备拿到 label
+  await loadDevices()
+  // 若此时已选中某个设备，重新启动预览确保走明确 deviceId（避免浏览器默认设备切换）
+  if (hasPermission.value && (selectedVideoId.value || selectedAudioId.value)) {
+    await startPreview()
+  }
+})
+
+onBeforeUnmount(() => {
+  stopPreviewStream()
+  stopAudioMeter()
+})
+</script>
+
+<style scoped>
+.page { min-height: 100vh; background: #F8FAFC; padding: 24rpx; }
+.container { max-width: 960rpx; margin: 0 auto; }
+.title { font-size: 40rpx; font-weight: 600; color: #0F172A; display: block; margin: 24rpx 0 8rpx; }
+.subtitle { font-size: 26rpx; color: #64748B; display: block; margin-bottom: 24rpx; }
+
+.content {
+  display: flex;
+  gap: 24rpx;
+  flex-wrap: wrap;
+}
+.preview-box {
+  flex: 1.4 1 400rpx;
+  min-width: 360rpx;
+  background: #FFFFFF;
+  border-radius: 16rpx;
+  padding: 20rpx;
+  box-shadow: 0 2rpx 8rpx rgba(15, 23, 42, 0.04);
+  display: flex;
+  flex-direction: column;
+  gap: 16rpx;
+}
+.video-slot {
+  width: 100%;
+  aspect-ratio: 4 / 3;
+  min-height: 360rpx;
+  background: #0B1220;
+  border-radius: 12rpx;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  overflow: hidden;
+}
+.preview-footer { display: flex; flex-direction: column; gap: 8rpx; }
+.volume-wrap { display: flex; flex-direction: column; gap: 6rpx; }
+.volume-label { font-size: 22rpx; color: #64748B; }
+.volume-bar {
+  width: 100%;
+  height: 10rpx;
+  background: #E2E8F0;
+  border-radius: 6rpx;
+  overflow: hidden;
+}
+.volume-fill {
+  height: 100%;
+  background: linear-gradient(90deg, #10B981 0%, #3B82F6 60%, #F59E0B 90%);
+  transition: width 0.08s linear;
+}
+.error { color: #EF4444; font-size: 22rpx; }
+
+.controls {
+  flex: 1 1 300rpx;
+  min-width: 280rpx;
+  background: #FFFFFF;
+  border-radius: 16rpx;
+  padding: 32rpx;
+  box-shadow: 0 2rpx 8rpx rgba(15, 23, 42, 0.04);
+}
+.field { margin-bottom: 24rpx; }
+.field:last-child { margin-bottom: 0; }
+.label { font-size: 28rpx; color: #1E293B; font-weight: 500; display: block; margin-bottom: 10rpx; }
+.picker, .input {
+  width: 100%;
+  padding: 18rpx 24rpx;
+  background: #F1F5F9;
+  border-radius: 12rpx;
+  font-size: 28rpx;
+  color: #0F172A;
+  border: 1px solid transparent;
+  box-sizing: border-box;
+}
+.picker {
+  min-height: 68rpx;
+  line-height: 32rpx;
+  display: flex;
+  align-items: center;
+}
+.switch-row {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+}
+.switch-label { flex: 1; }
+
+.actions { display: flex; gap: 24rpx; margin-top: 32rpx; }
+.btn {
+  flex: 1;
+  padding: 24rpx 0;
+  border-radius: 12rpx;
+  font-size: 30rpx;
+  font-weight: 500;
+  border: none;
+}
+.btn-secondary { background: #F1F5F9; color: #475569; }
+.btn-primary { background: #3B82F6; color: #FFFFFF; }
+.btn-primary[disabled], .btn-secondary[disabled] { opacity: 0.6; }
+</style>

frontend/src/store/meeting.js

@@ -104,6 +104,27 @@ export const useMeetingStore = defineStore('meeting', () => {
    */
   const remoteConsumers = reactive({})
 
+  /**
+   * 创建会议表单草稿（Task 10）
+   * create.vue 填完表单后暂存于此，preview.vue 点"加入会议"时才真正调用 createAndEnter。
+   * 字段：{ title, password?, enter_muted, allow_chat }
+   */
+  const draftCreatePayload = ref(null)
+
+  /**
+   * 设备预览页的设备选择与显示名（Task 10）
+   * preview.vue 选完设备后写入，入会时作为 mediaPrefs 传给 createAndEnter / joinAndEnter
+   * 字段：{ audioDeviceId, videoDeviceId, speakerDeviceId, displayName, startAudio, startVideo }
+   */
+  const devicePreview = ref({
+    audioDeviceId: '',
+    videoDeviceId: '',
+    speakerDeviceId: '',
+    displayName: '',
+    startAudio: true,
+    startVideo: true
+  })
+
   /**
    * 标记：当前在 Store 内的事件监听器集合（进房注册，离房注销）
    * Key 是事件名，Value 是监听函数引用
@@ -411,8 +432,14 @@ export const useMeetingStore = defineStore('meeting', () => {
 
   /**
    * 入会后的共同后置流程：加载 Device、创建两条 Transport、发 room.join 信令、订阅在线 Producer
+   * @param {Object} opts
+   * @param {Object} opts.rtpCapabilities - Router RTP capabilities
+   * @param {Object} [opts.mediaPrefs] - 设备预览页传入的媒体偏好，入会成功后自动推流
+   *   - startAudio: boolean 是否默认开麦
+   *   - startVideo: boolean 是否默认开摄像头
+   *   - audioDeviceId / videoDeviceId: 指定采集设备（可空→走系统默认）
    */
-  const _afterJoined = async ({ rtpCapabilities }) => {
+  const _afterJoined = async ({ rtpCapabilities, mediaPrefs }) => {
     if (!isMediaSupported()) {
       throw new Error('当前平台不支持会议（仅支持 H5 浏览器）')
     }
@@ -451,15 +478,28 @@ export const useMeetingStore = defineStore('meeting', () => {
     }
 
     localState.value = MEETING_LOCAL_STATE_CONNECTED
+
+    // mediaPrefs 自动推流：失败仅告警，不阻断入会流程，允许用户在会议室内手动重试开麦/开摄像头
+    if (mediaPrefs) {
+      if (mediaPrefs.startAudio) {
+        try { await startLocalAudio(mediaPrefs.audioDeviceId) }
+        catch (e) { _log('warn', '[Meeting] 自动开麦失败', e) }
+      }
+      if (mediaPrefs.startVideo) {
+        try { await startLocalVideo(mediaPrefs.videoDeviceId) }
+        catch (e) { _log('warn', '[Meeting] 自动开摄像头失败', e) }
+      }
+    }
   }
 
   // ==================== Actions：会议生命周期 ====================
 
   /**
    * 创建即时会议并立即入会
-   * @param {Object} payload - { title, password?, max_members? }
+   * @param {Object} payload - { title, password?, max_members?, enter_muted?, allow_chat? }
+   * @param {Object} [mediaPrefs] - 设备预览页的媒体偏好，入会成功后自动推流（可空）
    */
-  const createAndEnter = async (payload) => {
+  const createAndEnter = async (payload, mediaPrefs) => {
     if (isInMeeting.value) {
       throw new Error('你当前已在其他会议中')
     }
@@ -476,7 +516,7 @@ export const useMeetingStore = defineStore('meeting', () => {
         is_active: true,
         joined_at: new Date().toISOString()
       }
-      await _afterJoined({ rtpCapabilities: resp.rtp_capabilities })
+      await _afterJoined({ rtpCapabilities: resp.rtp_capabilities, mediaPrefs })
       return currentRoom.value
     } catch (err) {
       _log('error', '[Meeting] 创建并入会失败', err)
@@ -489,8 +529,9 @@ export const useMeetingStore = defineStore('meeting', () => {
    * 加入已有会议
    * @param {string} roomCode
    * @param {string} [password]
+   * @param {Object} [mediaPrefs] - 设备预览页的媒体偏好（可空）
    */
-  const joinAndEnter = async (roomCode, password = '') => {
+  const joinAndEnter = async (roomCode, password = '', mediaPrefs) => {
     if (isInMeeting.value) {
       throw new Error('你当前已在其他会议中')
     }
@@ -500,7 +541,7 @@ export const useMeetingStore = defineStore('meeting', () => {
       currentRoom.value = resp.room
       currentParticipant.value = resp.participant
       routerID.value = resp.router_id || ''
-      await _afterJoined({ rtpCapabilities: resp.rtp_capabilities })
+      await _afterJoined({ rtpCapabilities: resp.rtp_capabilities, mediaPrefs })
       return currentRoom.value
     } catch (err) {
       _log('error', '[Meeting] 加入会议失败', err)
@@ -540,22 +581,34 @@ export const useMeetingStore = defineStore('meeting', () => {
 
   // ==================== Actions：本地推流 ====================
 
-  /** 开启本地音频 */
+  /**
-  const startLocalAudio = async () => {
+   * 开启本地音频
+   * @param {string} [deviceId] - 指定麦克风 deviceId（从 enumerateDevices 获取），为空则走系统默认
+   */
+  const startLocalAudio = async (deviceId) => {
     if (!_engine) throw new Error('未连接')
     if (localProducers.audio) return
-    const stream = await navigator.mediaDevices.getUserMedia({ audio: true })
+    const audioConstraints = deviceId ? { deviceId: { exact: deviceId } } : true
+    const stream = await navigator.mediaDevices.getUserMedia({ audio: audioConstraints })
     const track = stream.getAudioTracks()[0]
     const producer = await _engine.produce({ kind: 'audio', track })
     localProducers.audio = producer.id
     localAudioEnabled.value = true
   }
 
-  /** 开启本地视频 */
+  /**
-  const startLocalVideo = async () => {
+   * 开启本地视频
+   * @param {string} [deviceId] - 指定摄像头 deviceId，为空则走系统默认
+   */
+  const startLocalVideo = async (deviceId) => {
     if (!_engine) throw new Error('未连接')
     if (localProducers.video) return
-    const stream = await navigator.mediaDevices.getUserMedia({ video: { width: 640, height: 480 } })
+    const videoConstraints = {
+      width: 640,
+      height: 480,
+      ...(deviceId ? { deviceId: { exact: deviceId } } : {})
+    }
+    const stream = await navigator.mediaDevices.getUserMedia({ video: videoConstraints })
     const track = stream.getVideoTracks()[0]
     const producer = await _engine.produce({ kind: 'video', track })
     localProducers.video = producer.id
@@ -671,6 +724,8 @@ export const useMeetingStore = defineStore('meeting', () => {
     localVideoEnabled,
     localProducers,
     remoteConsumers,
+    draftCreatePayload,
+    devicePreview,
 
     // getters
     isInMeeting,