feat: 新增心情打卡功能模块

实现心情打卡的完整功能，包括数据库表设计、API接口、业务逻辑和文档说明。支持记录多种心情类型、强度评分和统计分析功能。

src/mood-checkins/models/mood-checkin.model.ts

@@ -0,0 +1,97 @@
+import { Column, Model, Table, DataType, ForeignKey, BelongsTo } from 'sequelize-typescript';
+import { User } from '../../users/models/user.model';
+
+export enum MoodType {
+  HAPPY = 'happy',           // 开心
+  EXCITED = 'excited',       // 心动
+  THRILLED = 'thrilled',     // 兴奋
+  CALM = 'calm',             // 平静
+  ANXIOUS = 'anxious',       // 焦虑
+  SAD = 'sad',               // 难过
+  LONELY = 'lonely',         // 孤独
+  WRONGED = 'wronged',       // 委屈
+  ANGRY = 'angry',           // 生气
+  TIRED = 'tired'            // 心累
+}
+
+@Table({
+  tableName: 't_mood_checkins',
+  underscored: true,
+})
+export class MoodCheckin extends Model {
+  @Column({
+    type: DataType.UUID,
+    defaultValue: DataType.UUIDV4,
+    primaryKey: true,
+  })
+  declare id: string;
+
+  @ForeignKey(() => User)
+  @Column({
+    type: DataType.STRING,
+    allowNull: false,
+    comment: '用户ID',
+  })
+  declare userId: string;
+
+  @BelongsTo(() => User)
+  declare user: User;
+
+  @Column({
+    type: DataType.ENUM(...Object.values(MoodType)),
+    allowNull: false,
+    comment: '心情类型：喜怒哀乐',
+  })
+  declare moodType: MoodType;
+
+  @Column({
+    type: DataType.INTEGER,
+    allowNull: false,
+    defaultValue: 5,
+    comment: '心情强度（1-10）',
+    validate: {
+      min: 1,
+      max: 10,
+    },
+  })
+  declare intensity: number;
+
+  @Column({
+    type: DataType.TEXT,
+    allowNull: true,
+    comment: '心情描述',
+  })
+  declare description: string | null;
+
+  @Column({
+    type: DataType.DATEONLY,
+    allowNull: false,
+    comment: '打卡日期（YYYY-MM-DD）',
+  })
+  declare checkinDate: string;
+
+  @Column({
+    type: DataType.JSON,
+    allowNull: true,
+    comment: '扩展数据（标签、触发事件等）',
+  })
+  declare metadata: Record<string, any> | null;
+
+  @Column({
+    type: DataType.DATE,
+    defaultValue: DataType.NOW,
+  })
+  declare createdAt: Date;
+
+  @Column({
+    type: DataType.DATE,
+    defaultValue: DataType.NOW,
+  })
+  declare updatedAt: Date;
+
+  @Column({
+    type: DataType.BOOLEAN,
+    defaultValue: false,
+  })
+  declare deleted: boolean;
+}