style(web): 调整 AI 模式用户消息气泡布局与引用图标

- 用户消息气泡的操作区与时间右对齐
- 引用按钮图标由 mdi-reply 改为 mdi-format-quote-open

web/src/components/business/PersonalWorkbenchAiMode.vue

@@ -231,7 +231,7 @@
             </div>
             <div v-if="message.role === 'user'" class="workbench-ai-message-actions">
               <button type="button" title="引用" aria-label="引用" @click="quoteInlineMessage(message)">
-                <i class="mdi mdi-reply"></i>
+                <i class="mdi mdi-format-quote-open"></i>
               </button>
               <button type="button" title="复制" aria-label="复制" @click="copyInlineMessage(message)">
                 <i class="mdi mdi-content-copy"></i>