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/Infrastructure/Persistence/Migrations/MySql/20260724104203_CourseCategories.cs

@@ -0,0 +1,82 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
+{
+    /// <inheritdoc />
+    public partial class CourseCategories : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<Guid>(
+                name: "CourseCategoryId",
+                table: "Courses",
+                type: "char(36)",
+                nullable: true);
+
+            migrationBuilder.CreateTable(
+                name: "CourseCategories",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "char(36)", nullable: false),
+                    CreatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false),
+                    UpdatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false),
+                    Code = table.Column<string>(type: "varchar(40)", maxLength: 40, nullable: false),
+                    Name = table.Column<string>(type: "varchar(100)", maxLength: 100, nullable: false),
+                    SortOrder = table.Column<int>(type: "int", nullable: false),
+                    IsEnabled = table.Column<bool>(type: "tinyint(1)", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_CourseCategories", x => x.Id);
+                })
+                .Annotation("MySQL:Charset", "utf8mb4");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Courses_CourseCategoryId",
+                table: "Courses",
+                column: "CourseCategoryId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_CourseCategories_Code",
+                table: "CourseCategories",
+                column: "Code",
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_CourseCategories_IsEnabled_SortOrder",
+                table: "CourseCategories",
+                columns: new[] { "IsEnabled", "SortOrder" });
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_Courses_CourseCategories_CourseCategoryId",
+                table: "Courses",
+                column: "CourseCategoryId",
+                principalTable: "CourseCategories",
+                principalColumn: "Id",
+                onDelete: ReferentialAction.Restrict);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_Courses_CourseCategories_CourseCategoryId",
+                table: "Courses");
+
+            migrationBuilder.DropTable(
+                name: "CourseCategories");
+
+            migrationBuilder.DropIndex(
+                name: "IX_Courses_CourseCategoryId",
+                table: "Courses");
+
+            migrationBuilder.DropColumn(
+                name: "CourseCategoryId",
+                table: "Courses");
+        }
+    }
+}

src/Jiaowu.Api/Infrastructure/Persistence/Migrations/MySql/AppDbContextModelSnapshot.cs

@@ -329,6 +329,9 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.Property<Guid>("CollegeId")
                         .HasColumnType("char(36)");
 
+                    b.Property<Guid?>("CourseCategoryId")
+                        .HasColumnType("char(36)");
+
                     b.Property<DateTime>("CreatedAt")
                         .HasColumnType("datetime(6)");
 
@@ -375,6 +378,8 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.HasIndex("Code")
                         .IsUnique();
 
+                    b.HasIndex("CourseCategoryId");
+
                     b.HasIndex("CollegeId", "Nature");
 
                     b.HasIndex("IsEnabled", "SortOrder");
@@ -382,6 +387,44 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                     b.ToTable("Courses");
                 });
 
+            modelBuilder.Entity("Jiaowu.Api.Domain.Academic.CourseCategory", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("char(36)");
+
+                    b.Property<string>("Code")
+                        .IsRequired()
+                        .HasMaxLength(40)
+                        .HasColumnType("varchar(40)");
+
+                    b.Property<DateTime>("CreatedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.Property<bool>("IsEnabled")
+                        .HasColumnType("tinyint(1)");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasMaxLength(100)
+                        .HasColumnType("varchar(100)");
+
+                    b.Property<int>("SortOrder")
+                        .HasColumnType("int");
+
+                    b.Property<DateTime>("UpdatedAt")
+                        .HasColumnType("datetime(6)");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("Code")
+                        .IsUnique();
+
+                    b.HasIndex("IsEnabled", "SortOrder");
+
+                    b.ToTable("CourseCategories");
+                });
+
             modelBuilder.Entity("Jiaowu.Api.Domain.Academic.CourseEnrollment", b =>
                 {
                     b.Property<Guid>("Id")
@@ -1948,7 +1991,14 @@ namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
                         .OnDelete(DeleteBehavior.Restrict)
                         .IsRequired();
 
+                    b.HasOne("Jiaowu.Api.Domain.Academic.CourseCategory", "CourseCategory")
+                        .WithMany()
+                        .HasForeignKey("CourseCategoryId")
+                        .OnDelete(DeleteBehavior.Restrict);
+
                     b.Navigation("College");
+
+                    b.Navigation("CourseCategory");
                 });
 
             modelBuilder.Entity("Jiaowu.Api.Domain.Academic.CourseEnrollment", b =>