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.Client/Services/StudentSubmissionDetailService.cs

@@ -0,0 +1,26 @@
+using Entities.DTO;
+using TechHelper.Client.HttpRepository;
+using System.Net.Http.Json;
+
+namespace TechHelper.Client.Services
+{
+    public class StudentSubmissionDetailService : IStudentSubmissionDetailService
+    {
+        private readonly HttpClient _httpClient;
+
+        public StudentSubmissionDetailService(HttpClient httpClient)
+        {
+            _httpClient = httpClient;
+        }
+
+        public async Task<StudentSubmissionDetailDto> GetSubmissionDetailAsync(Guid submissionId)
+        {
+            var response = await _httpClient.GetAsync($"api/student-submission-detail/{submissionId}");
+            if (response.IsSuccessStatusCode)
+            {
+                return await response.Content.ReadFromJsonAsync<StudentSubmissionDetailDto>();
+            }
+            throw new HttpRequestException($"获取学生提交详细信息失败: {response.StatusCode}");
+        }
+    }
+}