chore：微信小程序也已显示思考过程

pages_tool/ai-chat/ai-chat-message.vue

@@ -76,12 +76,12 @@
           <view class="message-content">
             <!-- 思考流折叠面板 (AI 思考过程) -->
             <view v-if="message.role === 'ai' && message.thoughtsText" class="thought-panel" :class="{ streaming: message.isStreaming && message.thoughtsText }">
-              <view class="thought-header" @click="toggleThought(message)">
+              <view class="thought-header" @tap.stop="toggleThought(message)">
                 <text class="thought-icon">{{ message.isStreaming ? '🧠' : '💡' }}</text>
                 <text class="thought-label">{{ message.isStreaming ? '思考中...' : ('思考过程 (' + (message.thoughtSteps || 1) + ' 步)') }}</text>
-                <text v-if="!message.isStreaming" class="thought-toggle">{{ message.thoughtExpanded ? '▼' : '▶' }}</text>
+                <text v-if="!message.isStreaming" class="thought-toggle">{{ message.thoughtExpanded === false ? '▶' : '▼' }}</text>
               </view>
-              <view v-if="message.isStreaming || message.thoughtExpanded" class="thought-content">
+              <view v-if="message.isStreaming || message.thoughtExpanded !== false" class="thought-content">
                 <text>{{ message.thoughtsText }}</text>
               </view>
             </view>
@@ -1106,7 +1106,7 @@ async sendStreamMessage(userMessage, attachments = []) {
       pendingQuestion: null,
       questionAnswered: false,
       tokens: null,
-      thoughtExpanded: false,
+      thoughtExpanded: true,
       selectedAnswers: {},
       questionTimeout: 0
     }
@@ -3402,6 +3402,11 @@ _handleStreamError(msg) {
       /* AI消息特有样式 (微信风格: 头像 + 名称 + 时间同行, 下方内容)
          与你截图样式一致 */
       .ai-message {
+        .avatar {
+          /* 隐藏 AI 头像 */
+          display: none !important;
+        }
+
         .message-content {
           /* 确保昵称在内容上方的布局 */
           display: flex;