/**
 * Get the base URL for auth redirects.
 * Uses NEXT_PUBLIC_SITE_URL in production, falls back to window.location.origin for local dev.
 */
export function getBaseUrl(): string {
  if (process.env.NEXT_PUBLIC_SITE_URL) {
    return process.env.NEXT_PUBLIC_SITE_URL;
  }
  if (typeof window !== "undefined") {
    return window.location.origin;
  }
  return "http://localhost:3000";
}