chore: initialize wygj monorepo

backend/script/sql/update/update_5.3.0-5.3.1.sql

@@ -0,0 +1,7 @@
+ALTER TABLE `flow_node` DROP COLUMN `skip_any_node`;
+ALTER TABLE `flow_node`
+    ADD COLUMN `ext` text NULL COMMENT '扩展属性' AFTER `update_time`;
+ALTER TABLE `flow_user` ADD INDEX `user_associated`(`associated`) USING BTREE
+
+ALTER TABLE `sys_oss`
+    ADD COLUMN `ext1` text NULL COMMENT '扩展属性' AFTER `url`;