feat: 移除获取目标和任务详情的API及相关逻辑

- 删除GoalsController和GoalsService中获取单个目标和任务详情的API实现，简化代码结构。
- 更新GoalTaskService中的分页参数，将每页数量调整为200，提升数据处理能力。
- 优化GoalTaskQueryDto，移除页码和每页数量的验证装饰器，简化DTO结构。

src/goals/goals.service.ts

@@ -136,46 +136,6 @@ export class GoalsService {
     }
   }
 
-  /**
-   * 获取单个目标详情
-   */
-  async getGoal(userId: string, goalId: string): Promise<Goal> {
-    try {
-      // 惰性生成任务
-      await this.goalTaskService.generateTasksLazily(userId, goalId);
-
-      const goal = await this.goalModel.findOne({
-        where: { id: goalId, userId, deleted: false },
-        include: [
-          {
-            model: GoalCompletion,
-            as: 'completions',
-            where: { deleted: false },
-            required: false,
-            order: [['completedAt', 'DESC']],
-            limit: 10, // 只显示最近10次完成记录
-          },
-          {
-            model: GoalTask,
-            as: 'tasks',
-            where: { deleted: false },
-            required: false,
-            order: [['startDate', 'ASC']],
-            limit: 20, // 显示最近20个任务
-          },
-        ],
-      });
-
-      if (!goal) {
-        throw new NotFoundException('目标不存在');
-      }
-
-      return this.formatGoalResponse(goal);
-    } catch (error) {
-      this.logger.error(`获取目标详情失败: ${error.message}`);
-      throw error;
-    }
-  }
 
   /**
    * 更新目标