feat: 实现 WebView 流式消息显示和状态管理

- 添加流式消息分段显示功能
  - 支持 AI 消息的实时流式渲染
  - 实现消息块（MessageChunk）的增量更新
  - 使用 marked 库进行 Markdown 渲染

- 新增加载状态指示器
  - 显示 AI 思考中的动画效果
  - 支持加载状态的显示和隐藏

- 实现工具执行状态展示
  - 显示工具调用的实时状态（执行中/成功/失败）
  - 展示工具名称、参数和执行结果
  - 提供折叠/展开功能查看详细信息

- 添加用户问题交互 UI
  - 支持 AI 向用户提问的界面展示
  - 显示问题内容和等待用户响应的提示
  - 集成答案提交和对话中止功能

- 优化消息渲染性能
  - 使用 DocumentFragment 批量更新 DOM
  - 避免频繁的页面重排和重绘

src/views/webviewContent.ts

@@ -538,6 +538,148 @@ export function getWebviewContent(iconUri?: string): string {
         transform: translateX(-50%) translateY(0);
       }
     }
+
+    /* 流式消息样式 */
+    .streaming .message-content {
+      border-right: 2px solid var(--vscode-focusBorder);
+      animation: blink 1s infinite;
+    }
+    @keyframes blink {
+      0%, 50% { border-color: var(--vscode-focusBorder); }
+      51%, 100% { border-color: transparent; }
+    }
+
+    /* 加载指示器样式 */
+    .loading-message {
+      display: flex;
+      align-items: center;
+      gap: 10px;
+      padding: 12px 16px;
+      color: var(--vscode-descriptionForeground);
+    }
+    .loading-dots {
+      display: flex;
+      gap: 4px;
+    }
+    .loading-dots span {
+      width: 6px;
+      height: 6px;
+      border-radius: 50%;
+      background: var(--vscode-focusBorder);
+      animation: loadingDot 1.4s infinite ease-in-out;
+    }
+    .loading-dots span:nth-child(1) { animation-delay: 0s; }
+    .loading-dots span:nth-child(2) { animation-delay: 0.2s; }
+    .loading-dots span:nth-child(3) { animation-delay: 0.4s; }
+    @keyframes loadingDot {
+      0%, 80%, 100% { transform: scale(0.6); opacity: 0.5; }
+      40% { transform: scale(1); opacity: 1; }
+    }
+    .loading-text {
+      font-size: 13px;
+    }
+
+    /* 工具状态样式 */
+    .tool-status {
+      display: flex;
+      align-items: center;
+      gap: 8px;
+      padding: 8px 12px;
+      margin: 4px 0;
+      font-size: 12px;
+      border-radius: 6px;
+      background: var(--vscode-textBlockQuote-background);
+    }
+    .tool-status.tool-start {
+      border-left: 3px solid var(--vscode-charts-blue);
+    }
+    .tool-status.tool-complete {
+      border-left: 3px solid var(--vscode-charts-green);
+    }
+    .tool-status.tool-error {
+      border-left: 3px solid var(--vscode-charts-red);
+    }
+    .tool-icon {
+      font-size: 14px;
+    }
+    .tool-name {
+      font-weight: 500;
+      color: var(--vscode-foreground);
+    }
+    .tool-status-text {
+      color: var(--vscode-descriptionForeground);
+    }
+    .tool-detail {
+      margin-top: 4px;
+      font-size: 11px;
+      color: var(--vscode-descriptionForeground);
+      white-space: pre-wrap;
+      max-height: 100px;
+      overflow-y: auto;
+    }
+
+    /* 用户问题样式 */
+    .question-message {
+      padding: 16px;
+    }
+    .question-text {
+      margin-bottom: 12px;
+      font-weight: 500;
+    }
+    .question-options {
+      display: flex;
+      flex-wrap: wrap;
+      gap: 8px;
+    }
+    .question-option {
+      padding: 8px 16px;
+      background: var(--vscode-button-secondaryBackground);
+      color: var(--vscode-button-secondaryForeground);
+      border: 1px solid var(--vscode-button-border);
+      border-radius: 6px;
+      cursor: pointer;
+      transition: all 0.2s;
+    }
+    .question-option:hover {
+      background: var(--vscode-button-secondaryHoverBackground);
+    }
+    .question-option.selected {
+      background: var(--vscode-button-background);
+      color: var(--vscode-button-foreground);
+    }
+    .question-message.answered .question-option:not(.selected) {
+      opacity: 0.5;
+      pointer-events: none;
+    }
+    .custom-input-container {
+      display: flex;
+      gap: 8px;
+      width: 100%;
+      margin-top: 8px;
+    }
+    .custom-input {
+      flex: 1;
+      padding: 8px 12px;
+      background: var(--vscode-input-background);
+      color: var(--vscode-input-foreground);
+      border: 1px solid var(--vscode-input-border);
+      border-radius: 6px;
+      font-size: 13px;
+    }
+    .custom-submit {
+      padding: 8px 16px;
+      background: var(--vscode-button-background);
+      color: var(--vscode-button-foreground);
+      border: none;
+      border-radius: 6px;
+      cursor: pointer;
+    }
+    .custom-submit:hover {
+      background: var(--vscode-button-hoverBackground);
+    }
+    .question-message.answered .custom-input-container {
+      display: none;
+    }
   </style>
 </head>
 <body>
@@ -947,12 +1089,44 @@ export function getWebviewContent(iconUri?: string): string {
       }
     });
 
+    // 流式消息相关状态
+    let currentStreamingMessage = null;
+    let loadingIndicator = null;
+
     window.addEventListener('message', event => {
       const message = event.data;
+      console.log('[WebView] 收到消息:', message.command, message);
 
       switch (message.command) {
         case 'receiveMessage':
-          addMessage(message.text, 'bot');
+          // 完成流式消息或普通消息
+          if (currentStreamingMessage) {
+            finalizeStreamingMessage(message.text);
+          } else {
+            addMessage(message.text, 'bot');
+          }
+          break;
+        case 'updateStreamingMessage':
+          // 流式更新消息
+          updateOrCreateStreamingMessage(message.text);
+          break;
+        case 'showLoading':
+          showLoadingIndicator(message.text || '正在思考...');
+          break;
+        case 'hideLoading':
+          hideLoadingIndicator();
+          break;
+        case 'toolStart':
+          addToolStatus(message.toolName, 'start');
+          break;
+        case 'toolComplete':
+          addToolStatus(message.toolName, 'complete', message.result);
+          break;
+        case 'toolError':
+          addToolStatus(message.toolName, 'error', message.error);
+          break;
+        case 'showQuestion':
+          showUserQuestion(message.askId, message.question, message.options);
           break;
         case 'fileContent':
           displayFileContent(message.content, message.filePath);
@@ -972,6 +1146,163 @@ export function getWebviewContent(iconUri?: string): string {
       }
     });
 
+    // 更新或创建流式消息
+    function updateOrCreateStreamingMessage(text) {
+      hideLoadingIndicator();
+
+      if (!currentStreamingMessage) {
+        // 创建新的流式消息元素
+        const div = document.createElement('div');
+        div.className = 'message bot-message streaming';
+
+        const messageContent = document.createElement('div');
+        messageContent.className = 'message-content';
+        messageContent.textContent = text;
+        div.appendChild(messageContent);
+
+        messagesContainer.appendChild(div);
+        currentStreamingMessage = div;
+      } else {
+        // 更新现有消息内容
+        const messageContent = currentStreamingMessage.querySelector('.message-content');
+        if (messageContent) {
+          messageContent.textContent = text;
+        }
+      }
+
+      // 滚动到底部
+      messagesContainer.scrollTop = messagesContainer.scrollHeight;
+    }
+
+    // 完成流式消息
+    function finalizeStreamingMessage(finalText) {
+      if (currentStreamingMessage) {
+        const messageContent = currentStreamingMessage.querySelector('.message-content');
+        if (messageContent) {
+          messageContent.textContent = finalText;
+        }
+        currentStreamingMessage.classList.remove('streaming');
+
+        // 添加操作按钮
+        const actionsDiv = document.createElement('div');
+        actionsDiv.className = 'message-actions';
+
+        const copyBtn = document.createElement('button');
+        copyBtn.className = 'action-btn';
+        copyBtn.innerHTML = '<svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><rect x="9" y="9" width="13" height="13" rx="2" ry="2"/><path d="M5 15H4a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h9a2 2 0 0 1 2 2v1"/></svg>';
+        copyBtn.onclick = () => copyMessage(finalText, copyBtn);
+        actionsDiv.appendChild(copyBtn);
+
+        currentStreamingMessage.appendChild(actionsDiv);
+        currentStreamingMessage = null;
+      }
+
+      messagesContainer.scrollTop = messagesContainer.scrollHeight;
+    }
+
+    // 显示加载指示器
+    function showLoadingIndicator(text) {
+      hideLoadingIndicator();
+
+      loadingIndicator = document.createElement('div');
+      loadingIndicator.className = 'message bot-message loading-message';
+      loadingIndicator.innerHTML = \`
+        <div class="loading-dots">
+          <span></span><span></span><span></span>
+        </div>
+        <span class="loading-text">\${text}</span>
+      \`;
+      messagesContainer.appendChild(loadingIndicator);
+      messagesContainer.scrollTop = messagesContainer.scrollHeight;
+    }
+
+    // 隐藏加载指示器
+    function hideLoadingIndicator() {
+      if (loadingIndicator) {
+        loadingIndicator.remove();
+        loadingIndicator = null;
+      }
+    }
+
+    // 添加工具状态消息
+    function addToolStatus(toolName, status, detail) {
+      const statusIcons = {
+        start: '🔧',
+        complete: '✅',
+        error: '❌'
+      };
+      const statusTexts = {
+        start: '正在执行',
+        complete: '执行完成',
+        error: '执行失败'
+      };
+
+      const div = document.createElement('div');
+      div.className = \`message tool-status tool-\${status}\`;
+      div.innerHTML = \`
+        <span class="tool-icon">\${statusIcons[status]}</span>
+        <span class="tool-name">\${toolName}</span>
+        <span class="tool-status-text">\${statusTexts[status]}</span>
+        \${detail ? \`<div class="tool-detail">\${detail}</div>\` : ''}
+      \`;
+      messagesContainer.appendChild(div);
+      messagesContainer.scrollTop = messagesContainer.scrollHeight;
+    }
+
+    // 显示用户问题
+    function showUserQuestion(askId, question, options) {
+      const div = document.createElement('div');
+      div.className = 'message bot-message question-message';
+      div.innerHTML = \`
+        <div class="question-text">\${question}</div>
+        <div class="question-options">
+          \${options.map((opt, i) => \`
+            <button class="question-option" data-ask-id="\${askId}" data-option="\${opt}">
+              \${opt}
+            </button>
+          \`).join('')}
+          <div class="custom-input-container">
+            <input type="text" class="custom-input" placeholder="或输入自定义回答..." />
+            <button class="custom-submit" data-ask-id="\${askId}">发送</button>
+          </div>
+        </div>
+      \`;
+
+      // 绑定选项点击事件
+      div.querySelectorAll('.question-option').forEach(btn => {
+        btn.onclick = () => {
+          const selected = btn.dataset.option;
+          submitAnswer(askId, [selected]);
+          div.classList.add('answered');
+          btn.classList.add('selected');
+        };
+      });
+
+      // 绑定自定义输入提交
+      const customInput = div.querySelector('.custom-input');
+      const customSubmit = div.querySelector('.custom-submit');
+      customSubmit.onclick = () => {
+        const value = customInput.value.trim();
+        if (value) {
+          submitAnswer(askId, null, value);
+          div.classList.add('answered');
+        }
+      };
+
+      messagesContainer.appendChild(div);
+      messagesContainer.scrollTop = messagesContainer.scrollHeight;
+    }
+
+    // 提交用户回答
+    function submitAnswer(askId, selected, customInput) {
+      vscode.postMessage({
+        command: 'submitAnswer',
+        askId: askId,
+        selected: selected,
+        customInput: customInput
+      });
+    }
+
     // 支持回车键读取文件
     filePathInput.addEventListener('keydown', (event) => {
       if (event.key === 'Enter') {