成绩通知：仅在某门课程成绩正式发布后自动发送，按成绩单学生名单通知，不展示具体分数；发布状态与通知同一次提交。

手动发信：移除“成绩通知”选项，只能发送普通通知，原有角色与范围权限保持不变。
选课通知：管理员关闭一轮选课时，自动向每位参与学生发送一条汇总通知，包含最终选中课程及候补未成功课程；候补失效、轮次关闭和通知生成保持原子性。
关闭选课界面会明确提示发送通知，并显示实际通知人数。

src/Jiaowu.Api/Infrastructure/Persistence/Migrations/MySql/AppDbContextModelSnapshot.cs

@@ -2210,12 +2210,73 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.ToTable("MakeupExamSessionInvigilators");
                 });
 
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.MessageDispatch", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<Guid?>("AudienceId")
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("AudienceName")
+                        .IsRequired()
+                        .HasMaxLength(200)
+                        .HasColumnType("varchar(200)");
+
+                    b.Property<int>("AudienceType")
+                        .HasColumnType("int");
+
+                    b.Property<int>("Category")
+                        .HasColumnType("int");
+
+                    b.Property<string>("Content")
+                        .IsRequired()
+                        .HasMaxLength(1000)
+                        .HasColumnType("varchar(1000)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.Property<string>("LinkUrl")
+                        .HasMaxLength(300)
+                        .HasColumnType("varchar(300)");
+
+                    b.Property<int>("RecipientCount")
+                        .HasColumnType("int");
+
+                    b.Property<string>("SenderName")
+                        .IsRequired()
+                        .HasMaxLength(100)
+                        .HasColumnType("varchar(100)");
+
+                    b.Property<Guid>("SenderUserId")
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("Title")
+                        .IsRequired()
+                        .HasMaxLength(200)
+                        .HasColumnType("varchar(200)");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("SenderUserId", "CreatedAt");
+
+                    b.ToTable("MessageDispatches");
+                });
+
             modelBuilder.Entity("Jiaowu.Api.Domain.Academic.Notification", b =>
                 {
                     b.Property<Guid>("Id")
                         .ValueGeneratedOnAdd()
                         .HasColumnType("char(36)");
 
+                    b.Property<int>("Category")
+                        .HasColumnType("int");
+
                     b.Property<string>("Content")
                         .IsRequired()
                         .HasMaxLength(1000)
@@ -2231,6 +2292,9 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                         .HasMaxLength(300)
                         .HasColumnType("varchar(300)");
 
+                    b.Property<Guid?>("MessageDispatchId")
+                        .HasColumnType("char(36)");
+
                     b.Property<string>("Title")
                         .IsRequired()
                         .HasMaxLength(200)
@@ -2246,8 +2310,12 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
 
                     b.HasIndex("CreatedAt");
 
+                    b.HasIndex("MessageDispatchId");
+
                     b.HasIndex("UserId", "IsRead");
 
+                    b.HasIndex("UserId", "Category", "CreatedAt");
+
                     b.ToTable("Notifications");
                 });
 
@@ -4076,6 +4144,16 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.Navigation("Teacher");
                 });
 
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.Notification", b =>
+                {
+                    b.HasOne("Jiaowu.Api.Domain.Academic.MessageDispatch", "MessageDispatch")
+                        .WithMany("Notifications")
+                        .HasForeignKey("MessageDispatchId")
+                        .OnDelete(DeleteBehavior.Cascade);
+
+                    b.Navigation("MessageDispatch");
+                });
+
             modelBuilder.Entity("Jiaowu.Api.Domain.Academic.OfficialDocument", b =>
                 {
                     b.HasOne("Jiaowu.Api.Domain.Identity.ApplicationUser", "InvalidatedByUser")
@@ -4549,6 +4627,11 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.Navigation("Invigilators");
                 });
 
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.MessageDispatch", b =>
+                {
+                    b.Navigation("Notifications");
+                });
+
             modelBuilder.Entity("Jiaowu.Api.Domain.Academic.OfficialDocument", b =>
                 {
                     b.Navigation("Downloads");