fix: 录音格式改回 aac + 对话 UX 优化

录音:
- 从 mp3/16kHz/48kbps 改回原始工作配置 aac/22050Hz/16kbps
  (mp3 和 48kbps 在部分微信版本兼容不佳)
- 增加 recordingDuration ref 显示录音秒数
- onError 增加 JSON.stringify 打印详细错误原因
- 增加权限被拒的判断提示

UX 优化:
- 每条消息增加角色头像 (🤖 AI / 👤 用户)
- 增加 msg-body 容器 + msg-label 角色标签 (面试官/我)
- 对话布局改为左侧头像+气泡+名称，右侧用户头像+气泡
- msg-body max-width:70% 限制气泡宽度
- 麦克风按钮放大(80rpx)，增加文字标签「按住」/「Ns」
- 录音时禁用输入框(isRecording 时 textarea disabled)

zhiyin-app/src/pages/interview/interview.vue

@@ -38,10 +38,15 @@
     <!-- Chat area (both modes) -->
     <scroll-view class="chat-area" scroll-y :scroll-into-view="scrollToId" :scroll-with-animation="true" :class="{ 'chat-compact': avatarMode }">
       <view v-for="(msg, idx) in messages" :key="idx" :id="'msg-' + idx" class="msg-row" :class="msg.role">
+        <view v-if="msg.role === 'ai'" class="msg-avatar ai-avatar">🤖</view>
+        <view class="msg-body">
+          <view class="msg-label">{{ msg.role === 'ai' ? '面试官' : '我' }}</view>
           <view class="msg-bubble" :class="msg.role">
             <text>{{ msg.content }}</text>
           </view>
         </view>
+        <view v-if="msg.role === 'user'" class="msg-avatar user-avatar">👤</view>
+      </view>
 
       <view class="msg-row ai" v-if="aiLoading">
         <view class="typing">
@@ -56,10 +61,11 @@
 
     <view class="input-bar" v-if="!isComplete">
       <view class="mic-btn" :class="{ recording: isRecording }" @touchstart="startRecord" @touchend="stopRecord" @touchcancel="stopRecord" @mousedown="startRecord" @mouseup="stopRecord" @mouseleave="stopRecord">
-        <text class="mic-icon">🎤</text>
+        <text class="mic-icon">{{ isRecording ? '🔴' : '🎤' }}</text>
+        <text class="mic-label">{{ isRecording ? recordingDuration + 's' : '按住' }}</text>
       </view>
       <view class="input-box">
-        <textarea class="input-area" v-model="inputText" placeholder="输入你的回答..." :auto-height="true" :maxlength="2000" :disabled="aiLoading" @confirm="sendAnswer" />
+        <textarea class="input-area" v-model="inputText" placeholder="输入你的回答..." :auto-height="true" :maxlength="2000" :disabled="aiLoading || isRecording" @confirm="sendAnswer" />
       </view>
       <view class="send-btn" :class="{ disabled: (!inputText.trim() && !isRecording) || aiLoading }" @click="sendAnswer">
         <text class="send-icon">{{ isRecording ? '◉' : '➤' }}</text>
@@ -146,25 +152,31 @@ const aiAmplitudeData = ref([])
 const isSpeaking = ref(false)
 const dhRef = ref(null)
 const isRecording = ref(false)
+const recordingDuration = ref(0)
 let recorder = null
+let recordTimer = null
 
-
-// 录音初始化（一次性创建 recorder 并设置事件）
 function initRecorder() {
   // #ifdef MP-WEIXIN
-  if (recorder) return // 已初始化
+  if (recorder) return
   recorder = uni.getRecorderManager()
   recorder.onStart(() => {
     console.log('[Recorder] start recording')
+    recordingDuration.value = 0
+    recordTimer = setInterval(() => { recordingDuration.value++ }, 1000)
   })
   recorder.onError((err) => {
-    console.error('[Recorder] error:', err)
+    console.error('[Recorder] error:', JSON.stringify(err))
     isRecording.value = false
-    uni.showToast({ title: '录音失败，请重试', icon: 'none' })
+    recordingDuration.value = 0
+    if (recordTimer) { clearInterval(recordTimer); recordTimer = null }
+    const msg = err?.errMsg?.includes('permission') ? '请允许录音权限' : (err?.errMsg || '录音失败，请重试')
+    uni.showToast({ title: msg, icon: 'none' })
   })
   recorder.onStop(async (res) => {
     isRecording.value = false
-    console.log('[Recorder] stop, tempFilePath:', res.tempFilePath)
+    recordingDuration.value = 0
+    if (recordTimer) { clearInterval(recordTimer); recordTimer = null }
     if (!res.tempFilePath) {
       uni.showToast({ title: '录音文件为空', icon: 'none' })
       return
@@ -417,10 +429,10 @@ function startRecord() {
     return
   }
   recorder.start({
-    format: 'mp3',
+    format: 'aac',
-    sampleRate: 16000,
+    sampleRate: 22050,
     numberOfChannels: 1,
-    encodeBitRate: 48000,
+    encodeBitRate: 16000,
   })
   uni.vibrateShort({ type: 'medium' })
   // #endif
@@ -471,11 +483,20 @@ function stopRecord() {
 /* Chat */
 .chat-area { flex: 1; padding: 24rpx 20rpx; overflow-y: auto; }
 .chat-compact { max-height: 40vh; }
-.msg-row { display: flex; margin-bottom: 24rpx; }
+.msg-row { display: flex; margin-bottom: 32rpx; align-items: flex-start; gap: 12rpx; }
 .msg-row.ai { justify-content: flex-start; }
 .msg-row.user { justify-content: flex-end; }
 
-.msg-bubble { max-width: 560rpx; padding: 20rpx 24rpx; line-height: 1.7; font-size: 26rpx; }
+.msg-avatar { width: 48rpx; height: 48rpx; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 24rpx; flex-shrink: 0; }
+.ai-avatar { background: #EEF2FF; }
+.user-avatar { background: #FEF3C7; }
+
+.msg-body { max-width: 70%; display: flex; flex-direction: column; gap: 6rpx; }
+.msg-row.user .msg-body { align-items: flex-end; }
+
+.msg-label { font-size: 20rpx; color: #9CA3AF; padding: 0 8rpx; }
+
+.msg-bubble { padding: 20rpx 24rpx; line-height: 1.7; font-size: 26rpx; word-break: break-word; }
 .msg-bubble.ai {
   background: #FFFFFF; color: var(--color-text);
   border-radius: 0 var(--radius-lg) var(--radius-lg) var(--radius-lg);
@@ -509,13 +530,15 @@ function stopRecord() {
 .input-box { flex: 1; background: var(--color-bg); border-radius: var(--radius-md); padding: 12rpx 20rpx; }
 .input-area { width: 100%; font-size: 26rpx; color: var(--color-text); max-height: 160rpx; line-height: 1.5; }
 .mic-btn {
-  width: 64rpx; height: 64rpx; border-radius: 50%; background: #F3F4F6;
+  width: 80rpx; height: 80rpx; border-radius: 50%; background: #F3F4F6;
-  display: flex; align-items: center; justify-content: center; flex-shrink: 0;
+  display: flex; flex-direction: column; align-items: center; justify-content: center; flex-shrink: 0;
-  transition: all 0.2s;
+  transition: all 0.2s; gap: 2rpx;
 }
 .mic-btn:active { transform: scale(0.9); }
 .mic-btn.recording { background: #FEE2E2; animation: mic-pulse 1s infinite; }
-.mic-icon { font-size: 28rpx; }
+.mic-icon { font-size: 28rpx; line-height: 1; }
+.mic-label { font-size: 16rpx; color: #9CA3AF; line-height: 1; }
+.mic-btn.recording .mic-label { color: #EF4444; font-weight: 600; }
 @keyframes mic-pulse {
   0%, 100% { box-shadow: 0 0 0 0 rgba(239, 68, 68, 0.4); }
   50% { box-shadow: 0 0 0 16rpx rgba(239, 68, 68, 0); }