修复判断题和填空题的答题问题

## 主要修复
- 修复判断题答案验证：前端提交时将字符串转换为布尔值
- 修复判断题答案显示：支持布尔值和字符串格式的正确显示
- 修复判断题选项顺序：保持"正确"在前、"错误"在后
- 修复填空题答案残留：题目切换时自动清空填空输入框
- 优化填空题验证：去除前后空格，添加详细日志

## 技术细节
- Question.tsx: 判断题提交前将 "true"/"false" 转为 boolean
- AnswerResult.tsx: formatAnswer 函数支持 boolean 类型
- QuestionCard.tsx: 判断题不排序，填空题切换时重置状态
- practice_handler.go: 填空题比较前 TrimSpace，添加调试日志

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

internal/handlers/practice_handler.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"sort"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/gin-gonic/gin"
@@ -277,12 +278,18 @@ func checkPracticeAnswer(questionType string, userAnswer, correctAnswer interfac
 		userArr, ok1 := toStringArray(userAnswer)
 		correctArr, ok2 := toStringArray(correctAnswer)
 		if !ok1 || !ok2 || len(userArr) != len(correctArr) {
+			log.Printf("填空题验证失败 - 数组转换或长度不匹配: ok1=%v, ok2=%v, userLen=%d, correctLen=%d",
+				ok1, ok2, len(userArr), len(correctArr))
 			return false
 		}
 
-		// 逐个比较填空答案
+		// 逐个比较填空答案（去除前后空格）
 		for i := range correctArr {
-			if userArr[i] != correctArr[i] {
+			userTrimmed := strings.TrimSpace(userArr[i])
+			correctTrimmed := strings.TrimSpace(correctArr[i])
+			if userTrimmed != correctTrimmed {
+				log.Printf("填空题验证失败 - 第%d个答案不匹配: user='%s', correct='%s'",
+					i+1, userTrimmed, correctTrimmed)
 				return false
 			}
 		}
@@ -335,7 +342,7 @@ func convertToDTO(question models.PracticeQuestion) models.PracticeQuestionDTO {
 		dto.Answer = answer
 	}
 
-	// 判断题自动生成选项
+	// 判断题自动生成选项（正确在前，错误在后）
 	if question.Type == "true-false" {
 		dto.Options = []models.Option{
 			{Key: "true", Value: "正确"},

web/src/components/AnswerResult.tsx

@@ -17,14 +17,23 @@ const AnswerResult: React.FC<AnswerResultProps> = ({
   questionType,
 }) => {
   // 格式化答案显示（判断题特殊处理）
-  const formatAnswer = (answer: string | string[]) => {
-    const answerStr = Array.isArray(answer) ? answer.join(', ') : answer
-
+  const formatAnswer = (answer: string | string[] | boolean) => {
+    // 处理判断题的布尔值和字符串
     if (questionType === 'true-false') {
-      return answerStr === 'true' ? '正确' : answerStr === 'false' ? '错误' : answerStr
+      if (typeof answer === 'boolean') {
+        return answer ? '正确' : '错误'
+      }
+      if (typeof answer === 'string') {
+        return answer === 'true' ? '正确' : answer === 'false' ? '错误' : answer
+      }
     }
 
-    return answerStr
+    // 处理数组答案
+    if (Array.isArray(answer)) {
+      return answer.join(', ')
+    }
+
+    return String(answer)
   }
 
   return (

web/src/components/QuestionCard.tsx

@@ -1,4 +1,4 @@
-import React, { useState } from 'react'
+import React, { useState, useEffect } from 'react'
 import { Card, Space, Tag, Typography, Radio, Checkbox, Input, Button } from 'antd'
 import type { Question, AnswerResult as AnswerResultType } from '../types/question'
 import AnswerResult from './AnswerResult'
@@ -32,6 +32,13 @@ const QuestionCard: React.FC<QuestionCardProps> = ({
 }) => {
   const [fillAnswers, setFillAnswers] = useState<string[]>([])
 
+  // 当题目ID变化时，重置填空题答案
+  useEffect(() => {
+    if (question.type === 'fill-in-blank') {
+      setFillAnswers([])
+    }
+  }, [question.id, question.type])
+
   // 渲染填空题内容
   const renderFillContent = () => {
     const content = question.content
@@ -118,7 +125,10 @@ const QuestionCard: React.FC<QuestionCardProps> = ({
     }
 
     // 单选题和判断题
-    const sortedOptions = [...question.options].sort((a, b) => a.key.localeCompare(b.key))
+    // 判断题不排序，保持后端返回的顺序（正确在前，错误在后）
+    const sortedOptions = question.type === 'true-false'
+      ? question.options
+      : [...question.options].sort((a, b) => a.key.localeCompare(b.key))
 
     return (
       <Radio.Group

web/src/pages/Question.tsx

@@ -154,9 +154,15 @@ const QuestionPage: React.FC = () => {
 
     setLoading(true);
     try {
+      // 处理判断题答案：将字符串 "true"/"false" 转换为布尔值
+      let answerToSubmit = selectedAnswer;
+      if (currentQuestion.type === "true-false" && typeof selectedAnswer === "string") {
+        answerToSubmit = selectedAnswer === "true";
+      }
+
       const res = await questionApi.submitAnswer({
         question_id: currentQuestion.id,
-        answer: selectedAnswer,
+        answer: answerToSubmit,
       });
 
       if (res.success && res.data) {