已发布方案可修改名称、总学分、说明、课程模块及课程配置。

适用专业、入学年级、版本号保持锁定；前端禁用，后端也会返回 409 拒绝篡改。
归档方案仍只读。
修改已发布方案前增加即时生效警示和二次确认。

src/Jiaowu.Api/Controllers/CurriculumPlansController.cs

@@ -3,6 +3,7 @@ using Jiaowu.Api.Contracts;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Graduation;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
@@ -211,8 +212,16 @@ public sealed class CurriculumPlansController(
     {
         var plan = await EditablePlanAsync(id, cancellationToken);
         if (plan is null) return NotFound();
-        if (plan.Status != CurriculumPlanStatus.Draft)
-            return ConflictProblem("已发布或已归档的培养方案不可直接修改，请复制为新版本。");
+        if (!CurriculumPlanEditingPolicy.CanModifyContent(plan.Status))
+            return ConflictProblem("已归档的培养方案不可修改。");
+        if (!CurriculumPlanEditingPolicy.CanChangeApplicability(plan.Status) &&
+            (plan.MajorId != request.MajorId ||
+             plan.EffectiveGrade != request.EffectiveGrade ||
+             !string.Equals(plan.Version, request.Version.Trim(), StringComparison.Ordinal)))
+        {
+            return ConflictProblem(
+                "已发布方案可以修改名称、学分说明和课程结构；如需变更适用专业、入学年级或版本号，请复制为新版本。");
+        }
         var major = await FindAccessibleMajorAsync(request.MajorId, cancellationToken);
         if (major is null) return ValidationProblem("所选专业不存在或不在当前数据范围内。");
 
@@ -327,7 +336,7 @@ public sealed class CurriculumPlansController(
         CurriculumModuleRequest request,
         CancellationToken cancellationToken)
     {
-        var plan = await DraftPlanAsync(planId, cancellationToken);
+        var plan = await ModifiablePlanAsync(planId, cancellationToken);
         if (plan is null) return NotFound();
         var module = new CurriculumModule
         {
@@ -348,7 +357,7 @@ public sealed class CurriculumPlansController(
         CurriculumModuleRequest request,
         CancellationToken cancellationToken)
     {
-        if (await DraftPlanAsync(planId, cancellationToken) is null) return NotFound();
+        if (await ModifiablePlanAsync(planId, cancellationToken) is null) return NotFound();
         var module = await db.CurriculumModules
             .FirstOrDefaultAsync(x => x.Id == moduleId && x.CurriculumPlanId == planId, cancellationToken);
         if (module is null) return NotFound();
@@ -365,7 +374,7 @@ public sealed class CurriculumPlansController(
         Guid moduleId,
         CancellationToken cancellationToken)
     {
-        if (await DraftPlanAsync(planId, cancellationToken) is null) return NotFound();
+        if (await ModifiablePlanAsync(planId, cancellationToken) is null) return NotFound();
         var module = await db.CurriculumModules
             .FirstOrDefaultAsync(x => x.Id == moduleId && x.CurriculumPlanId == planId, cancellationToken);
         if (module is null) return NotFound();
@@ -380,7 +389,7 @@ public sealed class CurriculumPlansController(
         CurriculumCourseRequest request,
         CancellationToken cancellationToken)
     {
-        var plan = await DraftPlanAsync(planId, cancellationToken);
+        var plan = await ModifiablePlanAsync(planId, cancellationToken);
         if (plan is null) return NotFound();
         if (!await db.CurriculumModules.AnyAsync(
                 x => x.Id == moduleId && x.CurriculumPlanId == planId,
@@ -418,7 +427,7 @@ public sealed class CurriculumPlansController(
         CurriculumCourseRequest request,
         CancellationToken cancellationToken)
     {
-        var plan = await DraftPlanAsync(planId, cancellationToken);
+        var plan = await ModifiablePlanAsync(planId, cancellationToken);
         if (plan is null) return NotFound();
         var item = await db.CurriculumCourses
             .FirstOrDefaultAsync(x =>
@@ -454,7 +463,7 @@ public sealed class CurriculumPlansController(
         Guid itemId,
         CancellationToken cancellationToken)
     {
-        if (await DraftPlanAsync(planId, cancellationToken) is null) return NotFound();
+        if (await ModifiablePlanAsync(planId, cancellationToken) is null) return NotFound();
         var item = await db.CurriculumCourses
             .FirstOrDefaultAsync(x =>
                 x.Id == itemId &&
@@ -488,13 +497,15 @@ public sealed class CurriculumPlansController(
         CancellationToken cancellationToken) =>
         await ScopedPlans().FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
 
-    private async Task<CurriculumPlan?> DraftPlanAsync(
+    private async Task<CurriculumPlan?> ModifiablePlanAsync(
         Guid id,
         CancellationToken cancellationToken) =>
         await ScopedPlans()
             .Include(x => x.Major)
             .FirstOrDefaultAsync(
-                x => x.Id == id && x.Status == CurriculumPlanStatus.Draft,
+                x => x.Id == id &&
+                     (x.Status == CurriculumPlanStatus.Draft ||
+                      x.Status == CurriculumPlanStatus.Published),
                 cancellationToken);
 
     private Guid? ScopedCollegeId()

src/Jiaowu.Api/Infrastructure/Graduation/CurriculumPlanEditingPolicy.cs

@@ -0,0 +1,12 @@
+using Jiaowu.Api.Domain.Academic;
+
+namespace Jiaowu.Api.Infrastructure.Graduation;
+
+public static class CurriculumPlanEditingPolicy
+{
+    public static bool CanModifyContent(CurriculumPlanStatus status) =>
+        status is CurriculumPlanStatus.Draft or CurriculumPlanStatus.Published;
+
+    public static bool CanChangeApplicability(CurriculumPlanStatus status) =>
+        status == CurriculumPlanStatus.Draft;
+}