feat：更新依赖项的源地址，将所有依赖的镜像地址更改为官方的Yarn注册表地址，并在应用模块中引入新的Exercises模块。

src/exercises/models/exercise-category.model.ts

@@ -0,0 +1,41 @@
+import { Column, DataType, HasMany, Model, Table } from 'sequelize-typescript';
+import { Exercise } from './exercise.model';
+
+@Table({
+  tableName: 't_exercise_categories',
+  underscored: true,
+})
+export class ExerciseCategory extends Model {
+  @Column({
+    type: DataType.STRING,
+    primaryKey: true,
+    comment: '分类唯一键（英文/下划线）',
+  })
+  declare key: string;
+
+  @Column({
+    type: DataType.STRING,
+    allowNull: false,
+    comment: '分类中文名称',
+  })
+  declare name: string;
+
+  @Column({
+    type: DataType.INTEGER,
+    allowNull: false,
+    defaultValue: 0,
+    comment: '排序（升序）',
+  })
+  declare sortOrder: number;
+
+  @HasMany(() => Exercise, { foreignKey: 'categoryKey', sourceKey: 'key' })
+  declare exercises: Exercise[];
+
+  @Column({ type: DataType.DATE, defaultValue: DataType.NOW })
+  declare createdAt: Date;
+
+  @Column({ type: DataType.DATE, defaultValue: DataType.NOW })
+  declare updatedAt: Date;
+}
+
+