Verifiable Intent -- environment.* Constraint Family

The Verifiable Intent (VI) mandate format authorises autonomous agents to act on behalf of human principals through cryptographically signed constraint instances bound into Layer 2 mandates. VI's existing constraint families describe properties of the transaction itself — what is being purchased, by whom, for how much, against which credential. They do not describe properties of the environment in which the transaction is executed: whether the venue is open, whether the source of funds is funded, whether other relevant external conditions hold at the moment of execution. This document specifies the environment.* constraint family for the Verifiable Intent mandate vocabulary. It defines the membership criterion under which a constraint type qualifies as a member of the family, the family-wide vocabulary every member uses, the composition discipline by which family members compose with each other and with constraints from other families, the register discipline under which family-wide and per-type prose is written, the family-wide security considerations, and the IANA registry mechanics under which new family members are registered. It does not define any individual constraint type. Two reference type specifications (environment.market_state and environment.wallet_state) are referenced informatively in Appendix A.