选课批次：时间窗口、退课截止、学分上限、开放/关闭。

教学班投放：容量、班级范围、全校开放。
学生选退课：容量、重复课程、学分上限、课表冲突校验。
教学班实时名单。
校级、学院级、学生角色分级操作。
SQLite 本地增量升级及演示数据。
MySQL 正式 EF Core 迁移。
Vue 已编译进 wwwroot，单服务运行无需 npm run dev。
学生端和管理端均完成桌面、手机响应式检查。

src/Jiaowu.Api/Infrastructure/Persistence/DatabaseInitializer.cs

@@ -421,6 +421,42 @@ public sealed class DatabaseInitializer(
         }
 
         await SeedDevelopmentUsersAsync(computerCollege.Id);
+        await SeedDevelopmentCourseSelectionAsync();
+    }
+
+    private async Task SeedDevelopmentCourseSelectionAsync()
+    {
+        if (await db.CourseSelectionRounds.AnyAsync())
+        {
+            return;
+        }
+
+        var term = await db.AcademicTerms.SingleAsync(x => x.IsCurrent);
+        var task = await db.TeachingTasks.SingleAsync(
+            x => x.TaskNumber == "2026-1-CS101-01");
+        var now = DateTime.UtcNow;
+        db.CourseSelectionRounds.Add(new CourseSelectionRound
+        {
+            AcademicTermId = term.Id,
+            Name = "2026—2027 学年第一学期第一轮选课",
+            StartsAt = now.AddDays(-2),
+            EndsAt = now.AddDays(14),
+            WithdrawalEndsAt = now.AddDays(21),
+            MaxCredits = 30,
+            Status = CourseSelectionRoundStatus.Open,
+            Notes = "本地开发演示轮次，可用于验证选课、退课和教学班名单。",
+            Offerings =
+            [
+                new CourseSelectionOffering
+                {
+                    TeachingTaskId = task.Id,
+                    Capacity = 60,
+                    IsOpenToAll = false,
+                    Notes = "面向计科 2026-1 班开放。"
+                }
+            ]
+        });
+        await db.SaveChangesAsync();
     }
 
     private async Task SeedDevelopmentUsersAsync(Guid collegeId)