feat: 添加学生提交系统功能

- 添加学生提交管理服务 (StudentSubmissionService, StudentSubmissionDetailService)
- 新增学生提交相关控制器 (StudentSubmissionController, StudentSubmissionDetailController)
- 添加学生提交数据传输对象 (StudentSubmissionDetailDto, StudentSubmissionSummaryDto)
- 新增学生提交相关页面组件 (StudentExamView, ExamDetailView, StudentCard等)
- 添加学生提交信息卡片组件 (SubmissionInfoCard, TeacherSubmissionInfoCard)
- 更新数据库迁移文件以支持提交系统

TechHelper.Server/Services/IStudentSubmissionDetailService.cs

@@ -0,0 +1,15 @@
+using Entities.DTO;
+using TechHelper.Services;
+
+namespace TechHelper.Server.Services
+{
+    public interface IStudentSubmissionDetailService
+    {
+        /// <summary>
+        /// 获取学生提交的详细信息
+        /// </summary>
+        /// <param name="submissionId">提交ID</param>
+        /// <returns>学生提交详细信息</returns>
+        Task<ApiResponse> GetSubmissionDetailAsync(Guid submissionId);
+    }
+}