feat: 支持 AskUserQuestion 多问题和多选功能

- 新增 QuestionItem 类型支持单个问题配置（question/options/multiSelect）
   - AskUserEvent 改为 questions 数组支持多问题
   - AnswerRequest 新增 answers 字段支持多问题答案提交
   - 前端渲染支持单选按钮（radio）和多选复选框（checkbox）
   - 答案格式：{\"0\": [\"选项1\"], \"1\": [\"选项A\", \"选项B\"]}
   - 保持向后兼容旧的单问题格式

src/services/userInteraction.ts

@@ -4,7 +4,7 @@
  */
 import * as vscode from 'vscode';
 import { submitAnswer, submitToolConfirm } from './apiClient';
-import type { AskUserEvent, AnswerRequest } from '../types/api';
+import type { AskUserEvent, AnswerRequest, QuestionItem } from '../types/api';
 
 /**
  * 待处理的用户问题
@@ -12,8 +12,7 @@ import type { AskUserEvent, AnswerRequest } from '../types/api';
 interface PendingQuestion {
   askId: string;
   taskId: string;
-  question: string;
-  options: string[];
+  questions: QuestionItem[];
   resolve: (answer: string) => void;
   reject: (error: Error) => void;
 }
@@ -45,9 +44,9 @@ export class UserInteractionManager {
    * @param taskId 当前任务ID
    */
   async handleAskUser(event: AskUserEvent, taskId: string): Promise<void> {
-    const { askId, question, options } = event;
+    const { askId, questions } = event;
 
-    console.log(`[UserInteraction] 收到问题: askId=${askId}, question=${question}`);
+    console.log(`[UserInteraction] 收到问题: askId=${askId}, count=${questions.length}`);
 
     // 注意：问题显示已经通过 dialogService 的 onSegmentUpdate 统一处理
     // 这里不再单独发送 showQuestion 命令，避免重复显示
@@ -57,8 +56,7 @@ export class UserInteractionManager {
       this.pendingQuestions.set(askId, {
         askId,
         taskId,
-        question,
-        options,
+        questions,
         resolve: (answer: string) => {
           this.submitUserAnswer(askId, taskId, answer)
             .then(() => resolve())
@@ -80,24 +78,38 @@ export class UserInteractionManager {
   /**
    * 处理用户提交的回答（从 WebView 调用）
    * @param askId 问题ID
-   * @param selected 选中的选项
-   * @param customInput 自定义输入
+   * @param selected 选中的选项（旧格式）
+   * @param customInput 自定义输入（旧格式）
+   * @param answers 新格式：按问题索引的答案
    * @param fallbackTaskId 当问题不存在时使用的 taskId（用于直接发送到后端）
    */
   async receiveAnswer(
     askId: string,
     selected?: string[],
     customInput?: string,
+    answers?: { [questionIndex: string]: string[] },
     fallbackTaskId?: string
   ): Promise<void> {
     const pending = this.pendingQuestions.get(askId);
-    const answer = customInput || selected?.join(', ') || '';
+
+    // 构建答案字符串
+    let answer = '';
+    if (answers && Object.keys(answers).length > 0) {
+      // 新格式：多问题答案
+      answer = Object.entries(answers)
+        .sort(([a], [b]) => parseInt(a) - parseInt(b))
+        .map(([_, vals]) => vals.join('; '))
+        .join(' | ');
+    } else {
+      // 旧格式：单问题答案
+      answer = customInput || selected?.join(', ') || '';
+    }
 
     if (!pending) {
       // 问题不存在（可能是页面刷新或会话切换后），尝试直接发送到后端
       if (fallbackTaskId) {
         console.log(`[UserInteraction] 问题不在 pendingQuestions 中，直接发送到后端: askId=${askId}, taskId=${fallbackTaskId}`);
-        await this.submitUserAnswer(askId, fallbackTaskId, answer);
+        await this.submitUserAnswer(askId, fallbackTaskId, answer, answers);
       } else {
         console.warn(`[UserInteraction] 问题不存在且无 fallbackTaskId: askId=${askId}`);
       }
@@ -119,7 +131,8 @@ export class UserInteractionManager {
   private async submitUserAnswer(
     askId: string,
     taskId: string,
-    answer: string
+    answer: string,
+    answers?: { [questionIndex: string]: string[] }
   ): Promise<void> {
     // 检查是否是工具确认类型的问题
     if (askId.startsWith('tool_confirm_')) {
@@ -148,7 +161,8 @@ export class UserInteractionManager {
       const request: AnswerRequest = {
         askId,
         taskId,
-        customInput: answer
+        answers: answers,
+        customInput: answers ? undefined : answer
       };
 
       try {