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

Entities/Contracts/AssignmentQuestion.cs

@@ -40,6 +40,8 @@ namespace Entities.Contracts
 		[Column("group_state")]
 		public AssignmentStructType StructType { get; set; } = AssignmentStructType.Question;
 
+		public QuestionType Type { get; set; } = QuestionType.Unknown;
+
 		[Column("created_at")]
 		public DateTime CreatedAt { get; set; }