已改成“普通排课与实验学时分离”：

普通课表学时 = 总学时 − 实践学时。
自动排课、手工排课、课表发布都会阻止把实践学时重复排入。
全部为实践学时的课程应设为“非排时课程”，再由实验管理安排。
教学任务和排课页面会显示“常规 / 实践学时”。
已有教学任务即使仍保存旧周学时，排课时也会按拆分后的课程学时计算。
无需数据库迁移。

src/Jiaowu.Api/Controllers/SchedulesController.cs

@@ -6,6 +6,7 @@ using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Domain.System;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Jiaowu.Api.Infrastructure.Scheduling;
+using Jiaowu.Api.Infrastructure.Teaching;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
@@ -497,6 +498,7 @@ public sealed class SchedulesController(
             .Include(x => x.Classes)
             .ThenInclude(x => x.AdministrativeClass)
             .ThenInclude(x => x!.Students)
+            .Include(x => x.Course)
             .FirstOrDefaultAsync(x => x.Id == request.TeachingTaskId, cancellationToken);
          if (task is null ||
              task.Status != TeachingTaskStatus.Published ||
@@ -506,6 +508,27 @@ public sealed class SchedulesController(
              return ValidationProblem("非排时课程不进入正常课表，无需设置星期、节次或教室。");
         if (request.StartWeek < task.StartWeek || request.EndWeek > task.EndWeek)
             return ValidationProblem("排课周次必须位于教学任务的授课周次内。");
+        if (!TeachingTaskHours.TryResolveRegularWeeklyHours(
+                task.Course!,
+                task.StartWeek,
+                task.EndWeek,
+                out var requiredWeeklyHours))
+            return ValidationProblem(
+                "该课程的普通排课学时不能按授课周次整除，请先调整教学任务周次。");
+        if (requiredWeeklyHours == 0)
+            return ValidationProblem(
+                "该课程全部为实践学时，无需进入普通课表，请在实验管理中安排。");
+        var existingHours = await db.ScheduleEntries.AsNoTracking()
+            .Where(x =>
+                x.SchedulePlanId == plan.Id &&
+                x.TeachingTaskId == request.TeachingTaskId &&
+                x.Id != entryId)
+            .SumAsync(x => x.PeriodCount, cancellationToken);
+        if (existingHours + request.PeriodCount > requiredWeeklyHours)
+            return ValidationProblem(
+                $"该教学任务普通课表每周只需 {requiredWeeklyHours} 学时；" +
+                $"当前操作后将达到 {existingHours + request.PeriodCount} 学时，" +
+                "实践学时请在实验管理中安排。");
 
         var constraint = await db.TeachingTaskScheduleConstraints.AsNoTracking()
             .Include(x => x.AllowedClassrooms)