优化训练计划相关服务，移除不必要的completed字段，简化DTO和模型结构。同时，增强训练会话删除逻辑，添加事务处理和错误日志记录，提升数据一致性和操作安全性。

src/workouts/workouts.service.ts

@@ -109,7 +109,11 @@ export class WorkoutsService {
     });
 
     if (!activeTrainingPlan) {
-      throw new NotFoundException('请先激活一个训练计划');
+      this.winstonLogger.info(`今日没有激活的训练计划`, {
+        context: 'WorkoutsService',
+        userId,
+      });
+      return null;
     }
 
     // 创建今日训练会话
@@ -352,28 +356,44 @@ export class WorkoutsService {
    * 删除训练会话
    */
   async deleteWorkoutSession(userId: string, sessionId: string) {
-    const [count] = await this.workoutSessionModel.update(
-      { deleted: true },
-      { where: { id: sessionId, userId, deleted: false } }
-    );
+    const transaction = await this.workoutSessionModel.sequelize?.transaction();
+    if (!transaction) throw new Error('Failed to start transaction');
 
-    if (count === 0) {
-      throw new NotFoundException('训练会话不存在');
+    try {
+      const [count] = await this.workoutSessionModel.update(
+        { deleted: true },
+        { where: { id: sessionId, userId, deleted: false }, transaction }
+      );
+
+      if (count === 0) {
+        throw new NotFoundException('训练会话不存在');
+      }
+
+      // 同时删除关联的训练动作
+      await this.workoutExerciseModel.update(
+        { deleted: true },
+        { where: { workoutSessionId: sessionId, userId, deleted: false }, transaction }
+      );
+
+      await transaction.commit();
+
+      this.winstonLogger.info(`删除训练会话 ${sessionId}`, {
+        context: 'WorkoutsService',
+        userId,
+        sessionId,
+      });
+
+      return { success: true };
+    } catch (error) {
+      await transaction.rollback();
+      this.winstonLogger.error(`删除训练会话失败 ${sessionId}`, {
+        context: 'WorkoutsService',
+        userId,
+        sessionId,
+        error,
+      });
+      throw error;
     }
-
-    // 同时删除关联的训练动作
-    await this.workoutExerciseModel.update(
-      { deleted: true },
-      { where: { workoutSessionId: sessionId, userId, deleted: false } }
-    );
-
-    this.winstonLogger.info(`删除训练会话 ${sessionId}`, {
-      context: 'WorkoutsService',
-      userId,
-      sessionId,
-    });
-
-    return { success: true };
   }
 
   // ==================== 训练动作管理 ====================