feat(oa_city): add city_code and province_name columns - fix Unknown column 'city_code' error caused by Java Entity fields missing in DDL

sql/oa_city.sql

@@ -4,6 +4,8 @@ CREATE TABLE oa_city (
   city_id     BIGINT       NOT NULL AUTO_INCREMENT COMMENT '城市主键ID',
   country_name VARCHAR(64)  NOT NULL COMMENT '国家',
   city_name    VARCHAR(64)  NOT NULL COMMENT '城市',
+  city_code    VARCHAR(32)  DEFAULT NULL COMMENT '城市编码',
+  province_name VARCHAR(64) DEFAULT NULL COMMENT '所属省份',
   status       BIGINT      DEFAULT 1 COMMENT '状态 1正常 0禁用',
   remark       VARCHAR(500) DEFAULT NULL COMMENT '备注',
   del_flag     TINYINT     DEFAULT 0 COMMENT '删除标志：0=正常，1=已删除',