feat(enlish-service): 新增自动判卷功能及学生单词记忆管理模块

- 支持数据库多语句查询，修改数据源连接配置增加allowMultiQueries参数
- 添加定时任务AutoJudgeExamWordsTask，实现每5秒自动触发判卷
- 增加ExamWordsJudge接口及其实现类ExamWordsJudgeImpl，完成考试判卷逻辑
- 新增多张数据库映射文件及对应Mapper，如ExamWordsDOMapper、ExamWordsJudgeResultDOMapper、StudentExamWordsDOMapper和WordMasteryLogDOMapper，支持相关数据操作
- 扩展PngUtil工具类，支持从答题卡图片中解析学生考试信息和识别未记忆单词
- 修改数据库表结构映射，新增word_mastery_log表和相关字段，管理学生单词记忆强度及复习次数
- 配置@EnableScheduling以启用定时任务调度功能
- 增加测试用例包括ExamWordsJudgeTest和WordMasteryLogInsertTest，验证判卷和学生单词记忆初始化功能
- 重命名测试类TestInsert为TestVocabularyBankInsert，提升代码语义清晰度

enlish-service/src/main/resources/mapper/StudentExamWordsDOMapper.xml

@@ -8,6 +8,7 @@
         <result column="is_completed" jdbcType="INTEGER" property="isCompleted" />
         <result column="start_data" jdbcType="TIMESTAMP" property="startData" />
     </resultMap>
+
     <insert id="insertStudentsExam">
         insert into student_exam_words
             (student_id, exam_words_id, is_completed, start_data)
@@ -17,5 +18,20 @@
         </foreach>
     </insert>
 
+    <select id="selectByStudentIdAndExamWordsId" resultMap="BaseResultMap">
+        select *
+        from student_exam_words
+        where student_id = #{studentId}
+        and exam_words_id = #{examWordsId}
+        and is_completed = 0
+    </select>
+
+    <update id="updateStudentExamWordsFinished">
+        update student_exam_words
+        set is_completed = 1
+        where student_id = #{studentId}
+            and exam_words_id = #{examWordsId}
+            and is_completed = 0
+    </update>
 
 </mapper>