/**
 * Rill CLI - Describe project or runtime callables as a JSON contract
 *
 * Subcommands:
 *   project [--mount <name>] [--strict] [--config <path>]
 *     Describe extension surface (default when no subcommand given)
 *   handler [--strict] [--config <path>]
 *     Describe the project's own handler (main: "file.rill:name")
 *   builtins [--strict]
 *     Describe @rcrsr/rill runtime callables (no config needed)
 */
export declare function main(argv: string[]): Promise<number>;