fix: 录音可靠性修复 + ASR 后端优化

前端:
- recorder.onError 时重置 recorder = null，避免错误后录音永久失效
- 增加 asrLoading 状态，ASR 处理中输入框 disabled 并显示'语音识别中...'
- 增加 skipAsr 标志，<1s 的录音跳过 ASR 上传
- uploadFile 增加 30s timeout

后端:
- ASR: OpenAI 失败后 fallback 到本地 whisper，日志级别降为 warn
- try/catch/finally 重构，确保临时文件在所有路径都清理
- OpenAI 和 whisper 结果分别 try，互不影响

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

@@ -65,7 +65,7 @@
         <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 || isRecording" @confirm="sendAnswer" />
+        <textarea class="input-area" v-model="inputText" :placeholder="asrLoading ? '语音识别中...' : '输入你的回答...'" :auto-height="true" :maxlength="2000" :disabled="aiLoading || isRecording || asrLoading" @confirm="sendAnswer" />
       </view>
       <view class="send-btn" :class="{ disabled: (!inputText.trim() && !isRecording) || aiLoading }" @click="sendAnswer">
         <text class="send-icon">{{ isRecording ? '◉' : '➤' }}</text>
@@ -153,8 +153,10 @@ const isSpeaking = ref(false)
 const dhRef = ref(null)
 const isRecording = ref(false)
 const recordingDuration = ref(0)
+const asrLoading = ref(false)
 let recorder = null
 let recordTimer = null
+let skipAsr = false
 
 function initRecorder() {
   // #ifdef MP-WEIXIN
@@ -169,24 +171,29 @@ function initRecorder() {
     console.error('[Recorder] error:', JSON.stringify(err))
     isRecording.value = false
     recordingDuration.value = 0
+    asrLoading.value = false
     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 = null
   })
   recorder.onStop(async (res) => {
     isRecording.value = false
     recordingDuration.value = 0
     if (recordTimer) { clearInterval(recordTimer); recordTimer = null }
+    if (skipAsr) { skipAsr = false; return }
     if (!res.tempFilePath) {
       uni.showToast({ title: '录音文件为空', icon: 'none' })
       return
     }
+    asrLoading.value = true
     try {
       const uploadRes = await uni.uploadFile({
         url: api(API_ENDPOINTS.TTS.ASR),
         filePath: res.tempFilePath,
         name: 'audio',
         header: { 'Authorization': `Bearer ${token()}` },
+        timeout: 30000,
       })
       if (uploadRes.statusCode === 200 && uploadRes.data) {
         const data = typeof uploadRes.data === 'string' ? JSON.parse(uploadRes.data) : uploadRes.data
@@ -200,6 +207,8 @@ function initRecorder() {
       }
     } catch (e) {
       console.error('[ASR] upload error:', e?.message || e)
+    } finally {
+      asrLoading.value = false
     }
     uni.showToast({ title: '语音识别失败，请手动输入', icon: 'none' })
   })
@@ -418,7 +427,7 @@ const confirmExit = () => {
 }
 
 function startRecord() {
-  if (aiLoading.value || isComplete.value) return
+  if (aiLoading.value || isComplete.value || asrLoading.value) return
   // #ifdef MP-WEIXIN
   if (isRecording.value) return
   isRecording.value = true
@@ -445,6 +454,11 @@ function stopRecord() {
   if (!isRecording.value) return
   isRecording.value = false
   if (!recorder) return
+  if (recordingDuration.value < 1) {
+    skipAsr = true
+    if (recordTimer) { clearInterval(recordTimer); recordTimer = null }
+    recordingDuration.value = 0
+  }
   recorder.stop()
 }
 </script>