重构项目结构，移除Assignment相关功能，优化Submission模块

TechHelper.Client/Pages/Home.razor

@@ -1,12 +1,17 @@
 @page "/"
 @using Microsoft.AspNetCore.Authorization
 @using TechHelper.Client.Pages.Common.Exam
-
+@* 
 <AuthorizeView Roles="Student">
+	<Authorizing>
+		<p>Loading...</p>
+	</Authorizing>
 	<Authorized>
 		<TechHelper.Client.Pages.Student.HomePage />
 	</Authorized>
-</AuthorizeView>
+</AuthorizeView> *@
+
+<MudText>Hello</MudText>
 @code {
 	[CascadingParameter]
 	private Task<AuthenticationState> authenticationStateTask { get; set; }
@@ -14,6 +19,5 @@
 	protected override Task OnInitializedAsync()
 	{
 		return base.OnInitializedAsync();
-		Console.WriteLine(authenticationStateTask.Result.User.IsInRole("Student"));
 	}
 }