feat(ai-chat): 在流式回答中添加"思考中..."指示，优化操作栏显示逻辑

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

@@ -198,6 +198,25 @@
                   <!-- #endif -->
                 </view>
               </view>
+
+              <!-- PR-AI-STREAMING-TAIL (2026-09-28): AI 流式回答中, 在已显示内容下方追加 "思考中..." 指示
+                   仅当消息处于 streaming 状态且非 loading 占位时显示;
+                   流式结束 (isStreaming=false) 时自动消失, 与 .ai-actions 操作栏互补呈现 -->
+              <view
+                v-if="message.isStreaming && (message.type === 'text' || message.type === 'markdown')"
+                class="streaming-tail">
+                <view class="typing-dots-inline">
+                  <text class="dot"></text>
+                  <text class="dot"></text>
+                  <text class="dot"></text>
+                </view>
+                <text class="streaming-tail-text">{{ $lang('ai-chat.index.aiThinking') || '思考中' }}</text>
+                <text class="streaming-tail-ellipsis">
+                  <text class="ellipsis-dot">.</text>
+                  <text class="ellipsis-dot">.</text>
+                  <text class="ellipsis-dot">.</text>
+                </text>
+              </view>
               
               <!-- 文件链接 -->
               <view v-else-if="message.type === 'file'" class="file-content">
@@ -362,7 +381,8 @@
 
             <!-- AI 消息下方操作栏: 复制 / 点赞 / 不喜欢 / 更多 -->
             <!-- PR-CHAT-UI-CONFIG (2026-09-20): 后端可关闭 ui_enable_feedback (隐藏点赞/点踩/更多), 默认 true -->
-            <view class="ai-actions" v-if="message.role === 'ai' && message.type !== 'loading' && chatUiConfig.ui_enable_feedback">
+            <!-- PR-AI-ACTIONS-AFTER-DONE (2026-09-28): 仅在 AI 完全回答完成后才显示操作栏 (排除流式中), 避免一边打字一边出现复制/点赞按钮的"半成品"感 -->
+            <view class="ai-actions" v-if="message.role === 'ai' && message.type !== 'loading' && !message.isStreaming && chatUiConfig.ui_enable_feedback">
               <view class="ai-action-btn" @click="onAiActionCopy(message)">
                 <text class="iconfont icon-copy">⎘</text>
               </view>
@@ -4690,6 +4710,56 @@ _handleStreamError(msg) {
             display: none;
           }
 
+          // PR-AI-STREAMING-TAIL (2026-09-28): AI 流式回答中追加在内容末尾的"思考中..."指示
+          //   与 .ai-actions 互补: streaming 时只显示 tail, 操作栏等流式结束才显示
+          .streaming-tail {
+            display: flex;
+            align-items: center;
+            margin-top: 12rpx;
+            padding-top: 4rpx;
+            color: $color-primary;
+            font-size: 24rpx;
+            font-weight: 500;
+            line-height: 1;
+
+            .typing-dots-inline {
+              display: inline-flex;
+              align-items: center;
+              margin-right: 10rpx;
+
+              .dot {
+                width: 12rpx;
+                height: 12rpx;
+                border-radius: 50%;
+                background-color: $color-primary;
+                margin: 0 4rpx;
+                animation: dotPulse 1.5s infinite ease-in-out;
+
+                &:nth-child(2) { animation-delay: 0.2s; }
+                &:nth-child(3) { animation-delay: 0.4s; }
+              }
+            }
+
+            .streaming-tail-text {
+              color: $color-primary;
+              font-weight: 500;
+            }
+
+            .streaming-tail-ellipsis {
+              display: inline-flex;
+              margin-left: 4rpx;
+
+              .ellipsis-dot {
+                animation: ellipsisBlink 1.4s infinite ease-in-out;
+                opacity: 0;
+
+                &:nth-child(1) { animation-delay: 0s; }
+                &:nth-child(2) { animation-delay: 0.2s; }
+                &:nth-child(3) { animation-delay: 0.4s; }
+              }
+            }
+          }
+
           /* AI 消息下方操作栏: 复制 / 点赞 / 不喜欢 / 朗读 / 更多 */
           .ai-actions {
             margin-top: 12rpx;