课程库 Excel 导入导出已完成：

支持下载标准导入模板。
导出严格沿用当前关键词、学院、分类、课程性质和状态筛选。
以课程编码为唯一键：存在则更新，不存在则新增。
校验学院编码、课程分类、课程性质、学分学时及考核方式。
整批原子导入，任一行错误则全部不写入，并提示具体行号。
学院管理员仍只能维护本学院的专业课和实践课，无法借 Excel 越权。
界面入口沿用现有课程库工具栏样式。

src/Jiaowu.Api/Controllers/BaseDataController.cs

@@ -120,6 +120,44 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
             })
             .ToListAsync(cancellationToken));
 
+    [HttpGet("course-categories")]
+    public async Task<ActionResult<IReadOnlyCollection<CourseCategory>>> GetCourseCategories(
+        CancellationToken cancellationToken) =>
+        await db.CourseCategories.AsNoTracking()
+            .OrderBy(x => x.SortOrder)
+            .ThenBy(x => x.Code)
+            .ToListAsync(cancellationToken);
+
+    [HttpPost("course-categories")]
+    [Authorize(Roles = Administrators)]
+    public async Task<ActionResult<CourseCategory>> CreateCourseCategory(
+        CatalogRequest request,
+        CancellationToken cancellationToken)
+    {
+        var entity = new CourseCategory
+        {
+            Code = request.Code.Trim(),
+            Name = request.Name.Trim(),
+            SortOrder = request.SortOrder,
+            IsEnabled = request.IsEnabled
+        };
+        return await CreateAsync(entity, nameof(GetCourseCategories), cancellationToken);
+    }
+
+    [HttpPut("course-categories/{id:guid}")]
+    [Authorize(Roles = Administrators)]
+    public async Task<ActionResult<CourseCategory>> UpdateCourseCategory(
+        Guid id,
+        CatalogRequest request,
+        CancellationToken cancellationToken)
+    {
+        var entity = await db.CourseCategories.FindAsync([id], cancellationToken);
+        if (entity is null) return NotFound();
+        ApplyCatalog(entity, request);
+        await db.SaveChangesAsync(cancellationToken);
+        return entity;
+    }
+
     [HttpPost("majors")]
     [Authorize(Roles = Administrators)]
     public async Task<ActionResult<Major>> CreateMajor(
@@ -403,6 +441,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
             "terms" => await db.AcademicTerms.FindAsync([id], cancellationToken),
             "buildings" => await db.Buildings.FindAsync([id], cancellationToken),
             "classrooms" => await db.Classrooms.FindAsync([id], cancellationToken),
+            "course-categories" => await db.CourseCategories.FindAsync([id], cancellationToken),
             _ => null
         };