fix: voice input recording format + ASR logging

- Change recorder format from mp3 (8kHz) to aac (22kHz) for better
  whisper ASR accuracy
- Move recorder.onStop binding before recorder.stop() to prevent
  race condition (onStop may fire before handler is registered)
- Backend: add Logger, log ASR errors instead of silent catch {}
- Backend: change default extension from .mp3 to .aac

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

@@ -351,19 +351,7 @@ function startRecord() {
   isRecording.value = true
   recorder = uni.getRecorderManager()
   recorder.onStart(() => {})
-  recorder.onError(() => { isRecording.value = false })
-  recorder.start({ format: 'mp3' })
-  uni.vibrateShort({ type: 'medium' })
-  // #endif
-  // #ifndef MP-WEIXIN
-  uni.showToast({ title: '语音输入仅支持小程序', icon: 'none' })
-  // #endif
-}
-
-function stopRecord() {
-  if (!recorder || !isRecording.value) return
-  isRecording.value = false
-  recorder.stop()
+  recorder.onError(() => { isRecording.value = false; uni.showToast({ title: '录音失败', icon: 'none' }) })
   recorder.onStop(async (res) => {
     if (!res.tempFilePath) return
     const audioPath = res.tempFilePath
@@ -387,6 +375,18 @@ function stopRecord() {
     }
     uni.showToast({ title: '语音识别失败，请手动输入', icon: 'none' })
   })
+  recorder.start({ format: 'aac', sampleRate: 22050, numberOfChannels: 1, encodeBitRate: 16000 })
+  uni.vibrateShort({ type: 'medium' })
+  // #endif
+  // #ifndef MP-WEIXIN
+  uni.showToast({ title: '语音输入仅支持小程序', icon: 'none' })
+  // #endif
+}
+
+function stopRecord() {
+  if (!recorder || !isRecording.value) return
+  isRecording.value = false
+  recorder.stop()
 }
 </script>