chore: update default user limit to 1 million

Changed the default user limit from 10 million to 1 million
to better manage resource allocation and performance.

Author: trae-op

src/data/users.ts

@@ -28,7 +28,7 @@ export const cities = [
 
 export const ages = [22, 26, 30, 34, 38, 42];
 
-export const defaultLimit = 10_000_000;
+export const defaultLimit = 1_000_000;
 
 export const users: User[] = Array.from(
   { length: defaultLimit },