Try a paid agent call in one command

Trying x402 used to mean writing a client first, which is where most people stopped. `npx try-x402 --dry-run` now reads any x402 endpoint's payment terms and pays nothing. Drop the flag to pay for real. It works against any x402 server, not only DeskCrew, and it is MIT licensed. It refuses rather than trusts: USDC only, a price ceiling you set, authorizations that expire in ten minutes, and a signing domain built locally so a server cannot choose which contract your signature binds to.