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/Shared/ExamNavMenu.razor

@@ -1,22 +1,39 @@
 @using Microsoft.AspNetCore.Identity
 
 
-<ul class="nav nav-pills flex-column">
-    <li class="nav-item">
-        <NavLink class="nav-link" href="exam/create" Match="NavLinkMatch.All">创建</NavLink>
-    </li>
-    <li class="nav-item">
-        <NavLink class="nav-link" href="exam/manage">管理</NavLink>
-    </li>
-    <li class="nav-item">
-        <NavLink class="nav-link" href="Account/Manage/ChangePassword">Password</NavLink>
-    </li>
-@*     <li class="nav-item">
-        <NavLink class="nav-link" href="Account/Manage/TwoFactorAuthentication">Two-factor authentication</NavLink>
-    </li> *@
-</ul>
 
+<AuthorizeView Roles="Teacher">
+	<Authorized>
+
+		<ul class="nav nav-pills flex-column">
+			<li class="nav-item">
+				<NavLink class="nav-link" href="exam/create" Match="NavLinkMatch.All">创建</NavLink>
+			</li>
+			<li class="nav-item">
+				<NavLink class="nav-link" href="exam/manage">管理</NavLink>
+			</li>
+			<li class="nav-item">
+				<NavLink class="nav-link" href="Account/Manage/ChangePassword">Password</NavLink>
+			</li>
+		</ul>
+
+	</Authorized>
+</AuthorizeView>
+
+
+<AuthorizeView Roles="Student">
+	<Authorized>
+		<ul class="nav nav-pills flex-column">
+			<li class="nav-item">
+				<NavLink class="nav-link" href="exam/studentHomework" Match="NavLinkMatch.All">Homework</NavLink>
+			</li>
+			<li class="nav-item">
+				<NavLink class="nav-link" href="exam/manage">管理</NavLink>
+			</li>
+		</ul>
+	</Authorized>
+</AuthorizeView>
 @code {
-    private bool hasExternalLogins;
+	private bool hasExternalLogins;
 
 }