fix: un-revert prefectures :BocchiSobSmile: (#173)

Co-authored-by: alexay7 <43906716+alexay7@users.noreply.github.com>

AquaNet/src/libs/sdk.ts

@@ -196,6 +196,8 @@ export const USER = {
   },
   isLoggedIn,
   ensureLoggedIn,
+  changeRegion: (regionId: number) =>
+    post('/api/v2/user/change-region', { regionId }),
 }
 
 export const USERBOX = {