A gate closes against a number, an owner, and a fallback

concept

"Symmetry of rigor… every gate closes against a number, an owner and a fallback." Gate Zero is feasibility BEFORE form: the architecture is not permitted to proceed on enthusiasm, only on a first-order budget that closes. Numbers that are provisional are marked provisional — "design targets, not measured performance". WHERE IT ALREADY BEARS WEIGHT — Stronger than what this project's own gate does. `tools/check.py` closes against a number (coverage floors, 0 false positives, a real exit code) but names no OWNER and no FALLBACK for a failing gate. The punch list has completion tests; it does not say who answers for each or what happens if one cannot close. Worth adopting.