feat: 新增体重记录接口及枚举，优化AI教练选择项处理

src/activity-logs/models/activity-log.model.ts

@@ -4,6 +4,7 @@ import { User } from '../../users/models/user.model';
 export enum ActivityEntityType {
   USER = 'USER',
   USER_PROFILE = 'USER_PROFILE',
+  USER_WEIGHT_HISTORY = 'USER_WEIGHT_HISTORY',
   CHECKIN = 'CHECKIN',
   TRAINING_PLAN = 'TRAINING_PLAN',
   WORKOUT = 'WORKOUT',
@@ -37,7 +38,7 @@ export class ActivityLog extends Model {
   declare user?: User;
 
   @Column({
-    type: DataType.ENUM('USER', 'USER_PROFILE', 'CHECKIN', 'TRAINING_PLAN'),
+    type: DataType.ENUM('USER', 'USER_PROFILE', 'USER_WEIGHT_HISTORY', 'CHECKIN', 'TRAINING_PLAN', 'WORKOUT'),
     allowNull: false,
     comment: '实体类型',
   })