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

TechHelper.Server/Repository/ClassUserRepository.cs

@@ -0,0 +1,14 @@
+using Entities.Contracts;
+using Microsoft.EntityFrameworkCore;
+using SharedDATA.Api;
+using TechHelper.Context;
+
+namespace TechHelper.Repository
+{
+	public class ClassUserRepository : Repository<ClassUser>, IRepository<ClassUser>
+	{
+		public ClassUserRepository(ApplicationContext dbContext) : base(dbContext)
+		{
+		}
+	}
+}