增强自定义训练会话创建逻辑，添加详细日志记录以便于调试和错误追踪；调整训练会话查询排序方式，改为按创建时间排序。

src/workouts/workouts.service.ts

@@ -125,11 +125,17 @@ export class WorkoutsService {
     const transaction = await this.workoutSessionModel.sequelize?.transaction();
     if (!transaction) throw new Error('Failed to start transaction');
 
+    this.winstonLogger.info(`创建自定义训练会话`, {
+      context: 'WorkoutsService',
+      userId,
+      dto,
+    });
+
     try {
       // 1. 创建训练会话
       const workoutSession = await this.workoutSessionModel.create({
         userId,
-        trainingPlanId: null, // 自定义训练不关联训练计划
+
         name: dto.name,
         scheduledDate: dto.scheduledDate ? new Date(dto.scheduledDate) : new Date(),
         status: 'planned',
@@ -163,17 +169,23 @@ export class WorkoutsService {
         }
       }
 
-      await transaction.commit();
-
       this.winstonLogger.info(`创建自定义训练会话 ${workoutSession.id}`, {
         context: 'WorkoutsService',
         userId,
         workoutSessionId: workoutSession.id,
-          exerciseCount: dto.customExercises!.length,
+          exerciseCount: dto.customExercises?.length,
         });
 
+      await transaction.commit();
+      
       return workoutSession.toJSON();
     } catch (error) {
+      this.winstonLogger.error(`创建自定义训练会话失败`, {
+        context: 'WorkoutsService',
+        userId,
+        dto,
+        error,
+      });
       await transaction.rollback();
       throw error;
     }
@@ -309,7 +321,7 @@ export class WorkoutsService {
           attributes: ['id', 'name', 'goal']
         }
       ],
-      order: [['scheduledDate', 'DESC']],
+      order: [['createdAt', 'DESC']],
       limit,
       offset,
     });