重构作业结构：优化实体模型、DTO映射和前端界面

- 重构AppMainStruct、AssignmentQuestion、Question等实体模型
- 更新相关DTO以匹配新的数据结构
- 优化前端页面布局和组件
- 添加全局信息和笔记功能相关代码
- 更新数据库迁移和程序配置

TechHelper.Client/Helper/Helper.cs

@@ -0,0 +1,31 @@
+using MudBlazor;
+
+namespace TechHelper.Client.Helper
+{
+	public static class Helper
+	{
+		public static Color GetColorFromInt(int value)
+		{
+			var v = value % Enum.GetValues(typeof(Color)).Length;
+			switch (value)
+			{
+				case 1:
+					return MudBlazor.Color.Primary;
+				case 2:
+					return MudBlazor.Color.Secondary;
+				case 3:
+					return MudBlazor.Color.Success;
+				case 4:
+					return MudBlazor.Color.Info;
+				case 5:
+					return MudBlazor.Color.Warning;
+				case 6:
+					return MudBlazor.Color.Error;
+				case 7:
+					return MudBlazor.Color.Dark;
+				default:
+					return MudBlazor.Color.Default;
+			}
+		}
+	}
+}