nx_uxf_decode_gate.nx

nx_uxf_decode_gate.nx -- the D001 MIGRATION of nx_uxf_decode_test onto nx_gate_verdict (2026-09-06). This is the operator's HOUSE-OF-CARDS fix made mechanical: a reader that preserves fields it does not understand, proven by CID EQUALITY after a round-trip rather than by inspection. It is the load-bearing half of law 4 (data and functionality on independent clocks), and it was unpromotable because the original hand-rolls its counters and verdict line, so nothing outside could read its outcome. ALL FOUR TEETH PRESERVED IN ORDER AND PREDICATE. What changes: gv_check owns the counting so declared and executed cannot diverge, the neg-control is NAMED so the gate-law census can find it, and gv_kv emits the three CIDs and the field count so this gate's GREEN can be contradicted by anyone who re-encodes the record. license_tier: ORIGINAL No hw writes (Rule 26).