/**
 * openBrowser — best-effort cross-platform "open this URL in the default browser".
 *
 * Used by `openlife upgrade` to send the user to openlife.online to purchase.
 * Zero npm dependency (just node:child_process). It NEVER throws and NEVER
 * blocks: it spawns the OS launcher detached and returns whether the spawn was
 * issued. Callers MUST still print the URL as a fallback, because a `true`
 * return only means "a launcher was spawned", not "a browser actually opened".
 *
 * Security: only http(s) URLs are accepted. The URL is always passed as a
 * separate argv element (never interpolated into a shell string), so a
 * malicious URL cannot inject extra commands.
 */
/**
 * Open `url` in the default browser. Returns true if a launcher was spawned,
 * false if the URL was rejected or no launcher could be started.
 */
export declare function openBrowser(url: string): boolean;
