```

feat(setting): 添加跨库查询指定租户设置配置的功能

新增 getCrossDbSetting 方法，支持通过 XML 配置方式实现跨库查询指定租户的设置配置。该方法通过忽略租户拦截器，直接指定 tenant_id 进行数据查询，提升跨租户配置获取的灵活性和性能。
```

src/main/java/com/gxwebsoft/common/system/mapper/SettingMapper.java

@@ -37,4 +37,13 @@ public interface SettingMapper extends BaseMapper<Setting> {
 
     @InterceptorIgnore(tenantLine = "true")
     Setting getBySettingKeyIgnore(@Param("param") SettingParam param);
+
+    /**
+     * 跨库查询指定租户的设置配置
+     * @param settingKey 设置键
+     * @param tenantId 租户ID
+     * @return Setting
+     */
+    @InterceptorIgnore(tenantLine = "true")
+    Setting getCrossDbSetting(@Param("settingKey") String settingKey, @Param("tenantId") Integer tenantId);
 }

src/main/java/com/gxwebsoft/common/system/mapper/xml/SettingMapper.xml

@@ -30,4 +30,13 @@
     <include refid="selectSql"></include>
   </select>
 
+  <!-- 跨库查询指定租户的设置配置 -->
+  <select id="getCrossDbSetting" resultType="com.gxwebsoft.common.system.entity.Setting">
+    SELECT a.*
+    FROM gxwebsoft_core.sys_setting a
+    WHERE a.setting_key = #{settingKey}
+      AND a.tenant_id = #{tenantId}
+      AND a.deleted = 0
+  </select>
+
 </mapper>

src/main/java/com/gxwebsoft/common/system/service/impl/SettingServiceImpl.java

@@ -117,10 +117,8 @@ public class SettingServiceImpl extends ServiceImpl<SettingMapper, Setting> impl
       final List<Setting> list = list(new LambdaQueryWrapper<Setting>().eq(Setting::getTenantId, tenantId));
       System.out.println("跨租户获取指定租户的设置配置 list = " + list);
 
-        // 使用跨租户查询，指定租户ID
-        Setting setting = this.getOne(new QueryWrapper<Setting>()
-                .eq("setting_key", key)
-                .eq("tenant_id", tenantId), false);
+        // 使用跨租户查询，指定租户ID - 通过XML方式查询跨库数据（方式二：更简洁的方法）
+        Setting setting = baseMapper.getCrossDbSetting(key, tenantId);
 
         System.out.println("跨租户查询结果: " + setting);