feat: 添加顾客权限控制和订单时间限制

src/main/java/com/example/building/service/SystemConfigService.java

@@ -0,0 +1,43 @@
+package com.example.building.service;
+
+import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
+import com.example.building.entity.SystemConfig;
+import com.example.building.mapper.SystemConfigMapper;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import java.time.LocalDate;
+
+@Service
+public class SystemConfigService {
+
+    @Autowired
+    private SystemConfigMapper systemConfigMapper;
+
+    /**
+     * 获取顾客订单可见天数配置
+     * 默认180天（半年）
+     */
+    public int getCustomerOrderVisibleDays() {
+        LambdaQueryWrapper<SystemConfig> wrapper = new LambdaQueryWrapper<>();
+        wrapper.eq(SystemConfig::getConfigKey, "customer_order_visible_days");
+        SystemConfig config = systemConfigMapper.selectOne(wrapper);
+        
+        if (config != null && config.getConfigValue() != null) {
+            try {
+                return Integer.parseInt(config.getConfigValue());
+            } catch (NumberFormatException e) {
+                return 180;
+            }
+        }
+        return 180; // 默认半年
+    }
+
+    /**
+     * 获取顾客可见订单开始日期
+     */
+    public LocalDate getCustomerOrderStartDate() {
+        int days = getCustomerOrderVisibleDays();
+        return LocalDate.now().minusDays(days);
+    }
+}