§1 — Superseded lock (2026-07-04, same-day reversal)

First lock: vertical-canonical — "vertical everywhere; z stays an alias", by agent (lead steer: research and decide). Rationale: the vertical axis is frame-invariant (Z_cyl ≡ z_cart in the machine frame); the frame is already marked by the horizontal tokens (x/y vs radial/toroidal); the catalog was unanimous (46 vertical, 0 z) so zero churn; two canonical tokens for one physical axis risked recreating the family-splitting drift being fixed.

Why it was reopened the same day. The lead reviewed and steered: "reassess the need for a vertical vs z convention when we have family groups — it seems odd to have x, y, and vertical." The drift risk that motivated a single token is now covered by the codex vector-node family audit (each DD vector family must use one canonical triple), which did not exist when the first lock was made. With per-family enforcement, frame marking moves from the token level to the family level, and the mixed triple's readability cost (both the external reviewer and the lead tripped over it) dominates. Re-locked as z-in-cartesian-families in the evergreen plan.

Evergreen: independent-review-fixes.