refactor(chat): 优化语音输入组件逻辑

- 修改 WebSocket 接收数据逻辑，将实时文本追加到 existing value 中
- 移除未使用的 sendAsText 函数，简化代码结构

src/views/chat/components/VoiceInput.vue

@@ -117,7 +117,7 @@ const wsConfig = {
     try {
       const data = JSON.parse(event.data)
       if (data.text) {
-        realTimeText.value = data.text
+        realTimeText.value += data.text
       }
     } catch (error) {
       console.error('WebSocket message parse error:', error)
@@ -213,19 +213,6 @@ const confirmVoiceInput = async () => {
   closeVoiceModal()
 }
 
-const sendAsText = () => {
-  if (isRecording.value) {
-    stopRecording()
-    isRecording.value = false
-    
-    if (realTimeText.value) {
-      emit('sendText', realTimeText.value)
-    } else {
-      ElMessage.warning('没有识别到文字')
-    }
-  }
-  closeVoiceModal()
-}
 
 const startRecording = (stream) => {
   audioChunks = []