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。

tests/Jiaowu.Api.Tests/SchedulePublishJobProcessorTests.cs

@@ -12,7 +12,7 @@ public sealed class SchedulePublishJobProcessorTests
     [Fact]
     public async Task Processor_validates_and_publishes_plan_atomically()
     {
-        var result = await RunPublishAsync(weeklyHours: 2);
+        var result = await RunPublishAsync(weeklyHours: 2, scheduledHours: 2);
 
         Assert.Equal(SchedulePublishJobStatus.Succeeded, result.JobStatus);
         Assert.Equal(SchedulePlanStatus.Published, result.PlanStatus);
@@ -26,17 +26,46 @@ public sealed class SchedulePublishJobProcessorTests
     [Fact]
     public async Task Processor_keeps_draft_when_validation_fails()
     {
-        var result = await RunPublishAsync(weeklyHours: 4);
+        var result = await RunPublishAsync(weeklyHours: 2, scheduledHours: 1);
 
         Assert.Equal(SchedulePublishJobStatus.Failed, result.JobStatus);
         Assert.Equal(SchedulePlanStatus.Draft, result.PlanStatus);
         Assert.Null(result.ActiveAcademicTermId);
         Assert.Equal("检查未通过", result.CurrentStep);
-        Assert.Contains("尚未达到每周 4 学时", result.ErrorMessage);
+        Assert.Contains("尚未达到每周 2 个普通排课学时", result.ErrorMessage);
         Assert.Null(result.PublishedAt);
     }
 
-    private static async Task<PublishResult> RunPublishAsync(int weeklyHours)
+    [Fact]
+    public async Task Processor_excludes_practice_hours_for_existing_tasks()
+    {
+        var result = await RunPublishAsync(
+            weeklyHours: 2,
+            scheduledHours: 1,
+            practiceHours: 16);
+
+        Assert.Equal(SchedulePublishJobStatus.Succeeded, result.JobStatus);
+        Assert.Equal(SchedulePlanStatus.Published, result.PlanStatus);
+    }
+
+    [Fact]
+    public async Task Processor_rejects_practice_hours_already_added_to_draft()
+    {
+        var result = await RunPublishAsync(
+            weeklyHours: 2,
+            scheduledHours: 2,
+            practiceHours: 16);
+
+        Assert.Equal(SchedulePublishJobStatus.Failed, result.JobStatus);
+        Assert.Equal(SchedulePlanStatus.Draft, result.PlanStatus);
+        Assert.Contains("普通课表应为 1 学时", result.ErrorMessage);
+        Assert.Contains("删除已包含的实践学时", result.ErrorMessage);
+    }
+
+    private static async Task<PublishResult> RunPublishAsync(
+        int weeklyHours,
+        int scheduledHours,
+        int practiceHours = 0)
     {
         var databasePath = Path.Combine(
             Path.GetTempPath(),
@@ -75,7 +104,8 @@ public sealed class SchedulePublishJobProcessorTests
                     College = college,
                     Credits = 1,
                     TotalHours = 32,
-                    LectureHours = 32
+                    LectureHours = 32 - practiceHours,
+                    PracticeHours = practiceHours
                 };
                 var task = new TeachingTask
                 {
@@ -100,7 +130,7 @@ public sealed class SchedulePublishJobProcessorTests
                     TeachingTask = task,
                     DayOfWeek = 1,
                     StartPeriod = 1,
-                    PeriodCount = 2,
+                    PeriodCount = scheduledHours,
                     StartWeek = 1,
                     EndWeek = 16,
                     WeekPattern = WeekPattern.All