refactor(chat): 优化时间戳显示和处理

- 移除了对 createdAtTimestamp 的引用，改为使用 createdAt
- 添加了对时间戳的格式化处理，支持字符串和数字类型的时间戳
- 增加了时间戳的有效性检查
- 调整了时间戳的显示位置和样式

src/views/chat/ChatInterface.vue

@@ -21,9 +21,9 @@
             <el-avatar :src="userAvatarUrl" :size="40" class="avatar" />
             <div class="message-content">
               <div class="message-text-wrapper">
-                <!-- <div v-if="message.createdAt" class="message-timestamp">
-                  {{ formatTimestamp(message.createdAtTimestamp) }}
-                </div> -->
+                <div v-if="message.createdAt" class="message-timestamp">
+                  {{ formatTimestamp(message.createdAt) }}
+                </div>
                 <div class="message-text">{{ message.question }}</div>
               </div>
               <!-- 改进建议部分 -->
@@ -55,9 +55,9 @@
             <el-avatar :src="customAvatarUrl" :size="40" class="avatar" />
             <div class="message-content">
               <div class="message-text-wrapper">
-                <!-- <div v-if="message.createdAt" class="message-timestamp">
-                  {{ formatTimestamp(message.createdAtTimestamp) }}
-                </div> -->
+                <div v-if="message.createdAt" class="message-timestamp">
+                  {{ formatTimestamp(message.createdAt) }}
+                </div>
                 <div class="message-text">
                   <span v-html="message.kehu"></span>
                   <span v-if="message.respondingType === 'kehu'" class="typing-indicator">
@@ -310,9 +310,20 @@ const toggleSummary = () => {
 
 // 格式化时间戳
 const formatTimestamp = (timestamp) => {
-  console.log('%c timestamp:', 'color: #2196F3; font-weight: bold', timestamp)
   if (!timestamp) return ''
-  const date = new Date(timestamp)
+  
+  // 检查时间戳是否为字符串，如果是则转换为数字
+  const timestampNum = typeof timestamp === 'string' ? parseInt(timestamp) : timestamp
+  
+  // 检查时间戳是否为毫秒级，如果不是则转换为毫秒
+  const date = new Date(timestampNum.toString().length === 10 ? timestampNum * 1000 : timestampNum)
+  
+  // 检查日期是否有效
+  if (isNaN(date.getTime())) {
+    console.error('Invalid timestamp:', timestamp)
+    return ''
+  }
+  
   return date.toLocaleString('zh-CN', {
     year: 'numeric',
     month: '2-digit',
@@ -561,6 +572,9 @@ html.dark .background-section .background-content {
         flex-direction: column;
         align-items: flex-end;
       }
+      .message-timestamp {
+        right: 0;
+      }
     }
 
     &.assistant {
@@ -865,6 +879,7 @@ html.dark .background-section .background-content {
   top: -20px;
   opacity: 0;
   transition: opacity 0.2s ease;
+  width: max-content;
 }
 
 .message-text-wrapper {