feat(web,server): external domain setting (#6146)

* feat: external domain setting

* chore: open api

* mobile: handle serverconfig-externalDomain

---------

Co-authored-by: shenlong-tanwen <139912620+shalong-tanwen@users.noreply.github.com>

server/src/domain/system-config/system-config.core.ts

@@ -127,6 +127,9 @@ export const defaults = Object.freeze<SystemConfig>({
       cronExpression: CronExpression.EVERY_DAY_AT_MIDNIGHT,
     },
   },
+  server: {
+    externalDomain: '',
+  },
 });
 
 export enum FeatureFlag {