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/Infrastructure/Scheduling/AutomaticScheduleGenerator.cs

@@ -1,5 +1,6 @@
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Infrastructure.Persistence;
+using Jiaowu.Api.Infrastructure.Teaching;
 using Microsoft.EntityFrameworkCore;
 
 namespace Jiaowu.Api.Infrastructure.Scheduling;
@@ -34,6 +35,7 @@ public sealed class AutomaticScheduleGenerator(AppDbContext db)
             .Include(x => x.Classes)
             .ThenInclude(x => x.AdministrativeClass)
             .ThenInclude(x => x!.Students)
+            .Include(x => x.Course)
             .OrderByDescending(x => x.Classes.Count + x.Teachers.Count)
             .ThenByDescending(x => x.Capacity)
             .ThenBy(x => x.TaskNumber)
@@ -72,10 +74,43 @@ public sealed class AutomaticScheduleGenerator(AppDbContext db)
         {
             cancellationToken.ThrowIfCancellationRequested();
             constraints.TryGetValue(task.Id, out var constraint);
+            if (!TeachingTaskHours.TryResolveRegularWeeklyHours(
+                    task.Course!,
+                    task.StartWeek,
+                    task.EndWeek,
+                    out var requiredWeeklyHours))
+            {
+                messages.Add(
+                    $"{task.TaskNumber} · {task.Name} 的普通排课学时不能按授课周次整除，请调整教学任务周次。");
+                processedTasks++;
+                if (reportProgress is not null)
+                {
+                    await reportProgress(
+                        new(tasks.Count, processedTasks, created, completedTasks),
+                        cancellationToken);
+                }
+                continue;
+            }
+
             var scheduledHours = entries
                 .Where(x => x.TeachingTaskId == task.Id)
                 .Sum(x => x.PeriodCount);
-            var remainingHours = Math.Max(0, task.WeeklyHours - scheduledHours);
+            if (scheduledHours > requiredWeeklyHours)
+            {
+                messages.Add(
+                    $"{task.TaskNumber} · {task.Name} 已安排每周 {scheduledHours} 学时，" +
+                    $"普通课表只需 {requiredWeeklyHours} 学时；请删除已包含的实践学时。");
+                processedTasks++;
+                if (reportProgress is not null)
+                {
+                    await reportProgress(
+                        new(tasks.Count, processedTasks, created, completedTasks),
+                        cancellationToken);
+                }
+                continue;
+            }
+
+            var remainingHours = requiredWeeklyHours - scheduledHours;
             if (remainingHours == 0)
             {
                 completedTasks++;