nx_sign_envelope_gate.nx

nx_sign_envelope_gate.nx -- INDEPENDENT gate for the Nishi Sign core lib (imports the SAME shipped code the organ runs -- validation edge in the atlas, not a copy). Stronger than the organ's self-test: tamper at EVERY chain position, truncation-tamper, cross-envelope separation, persist round-trip. SELF-PUBLISHES its receipt to knowledge/status/office_sign_gate.log (the ecomat live-derive evidence pointer; needle "VERDICT=") -- evidence generated by the gate itself on the hub, never hand-asserted. license_tier: ORIGINAL