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/Controllers/StudentSubmissionDetailController.cs

@@ -0,0 +1,81 @@
+using Entities.Contracts;
+using Entities.DTO;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Identity;
+using Microsoft.AspNetCore.Mvc;
+using TechHelper.Server.Services;
+using TechHelper.Context;
+using TechHelper.Repository;
+using SharedDATA.Api;
+using System.Security.Claims;
+
+namespace TechHelper.Server.Controllers
+{
+    [Route("api/student-submission-detail")]
+    [ApiController]
+    [Authorize]
+    public class StudentSubmissionDetailController : ControllerBase
+    {
+    private readonly IStudentSubmissionDetailService _studentSubmissionDetailService;
+    private readonly UserManager<User> _userManager;
+    private readonly IUnitOfWork _unitOfWork;
+
+    public StudentSubmissionDetailController(
+        IStudentSubmissionDetailService studentSubmissionDetailService,
+        UserManager<User> userManager,
+        IUnitOfWork unitOfWork)
+    {
+        _studentSubmissionDetailService = studentSubmissionDetailService;
+        _userManager = userManager;
+        _unitOfWork = unitOfWork;
+    }
+
+        /// <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>
+        [HttpGet("{submissionId:guid}")]
+        public async Task<IActionResult> GetSubmissionDetail(Guid submissionId)
+        {
+            try
+            {
+                // 验证用户权限 - 只有学生本人或教师可以查看
+                var user = await _userManager.FindByEmailAsync(User.Identity.Name);
+                if (user == null)
+                {
+                    return NotFound("未找到用户信息");
+                }
+
+                var submission = await _unitOfWork.GetRepository<Submission>()
+                    .GetFirstOrDefaultAsync(predicate: s => s.Id == submissionId);
+
+                if (submission == null)
+                {
+                    return NotFound("未找到指定的提交记录");
+                }
+
+                // 检查权限：学生只能查看自己的提交，教师可以查看所有提交
+                if (user.Id != submission.StudentId && !User.IsInRole("Teacher"))
+                {
+                    return Forbid("您没有权限查看此提交记录");
+                }
+
+                var result = await _studentSubmissionDetailService.GetSubmissionDetailAsync(submissionId);
+
+                if (result.Status)
+                {
+                    return Ok(result.Result);
+                }
+                else
+                {
+                    return BadRequest(result.Message);
+                }
+            }
+            catch (Exception ex)
+            {
+                return StatusCode(500, $"获取学生提交详细信息失败: {ex.Message}");
+            }
+        }
+    }
+}