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.model.ts

@@ -0,0 +1,42 @@
+import { BelongsTo, Column, DataType, ForeignKey, Model, Table } from 'sequelize-typescript';
+import { ExerciseCategory } from './exercise-category.model';
+
+@Table({
+  tableName: 't_exercises',
+  underscored: true,
+})
+export class Exercise extends Model {
+  @Column({
+    type: DataType.STRING,
+    primaryKey: true,
+    comment: '动作唯一键（英文/下划线）',
+  })
+  declare key: string;
+
+  @Column({ type: DataType.STRING, allowNull: false, comment: '名称（含中英文）' })
+  declare name: string;
+
+  @Column({ type: DataType.STRING, allowNull: false, comment: '中文分类名（冗余，便于展示）' })
+  declare categoryName: string;
+
+  @Column({ type: DataType.TEXT, allowNull: false, comment: '描述' })
+  declare description: string;
+
+  @ForeignKey(() => ExerciseCategory)
+  @Column({ type: DataType.STRING, allowNull: false, comment: '分类键' })
+  declare categoryKey: string;
+
+  @BelongsTo(() => ExerciseCategory, { foreignKey: 'categoryKey', targetKey: 'key' })
+  declare category: ExerciseCategory;
+
+  @Column({ type: DataType.INTEGER, allowNull: false, defaultValue: 0, comment: '排序（分类内）' })
+  declare sortOrder: number;
+
+  @Column({ type: DataType.DATE, defaultValue: DataType.NOW })
+  declare createdAt: Date;
+
+  @Column({ type: DataType.DATE, defaultValue: DataType.NOW })
+  declare updatedAt: Date;
+}
+
+