re: monotone assignment refuted again -- box identity needs descriptor data

XBG7_MONOTONE=1 enforces descriptor order per (stride, vtx, idx) signature: 89
minority decodes, unchanged. Monotonicity constrains order WITHIN a container
while the disagreement is BETWEEN containers, which hold different numbers of
these boxes in different arrangements. The remaining 89 are bounding-box identity
ambiguities needing descriptor-level information, not another anchoring
heuristic. Knob kept, default off, measurement recorded; suites green.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

docs/re/structures/xbg7-mesh.md

@@ -1128,10 +1128,21 @@ rather than being the "one real disagreement" first written here.
 different containers.** What remains is 24-vertex boxes swapping identities: many
 of them exist, they are structurally identical, and distinct assignment gives each
 a *distinct* block without pinning *which* block belongs to which name. Fixing
-that needs an ordering rule (descriptor order ↔ ascending offset). Monotone
-anchoring was refuted once before, but that was measured under a decoder with
-several other defects, so it is worth re-testing — and it is now cheap to judge,
-because the target is a single number: 89 → 0.
+that needs an ordering rule (descriptor order ↔ ascending offset).
+
+**Re-tested, and refuted again.** `XBG7_MONOTONE=1` adds exactly that rule: per
+`(stride, vtx_count, idx_count)` signature, a later resource may not take an
+earlier block than the previous one of the same signature. Result: **89 minority
+decodes — unchanged.** The reason is structural. Monotonicity constrains the
+order *within* a container, but the disagreement is *between* containers, which
+hold different numbers of these boxes in different arrangements; a consistent
+within-container order does not force a consistent name↔box mapping across them.
+
+So the remaining 89 are **bounding-box identity ambiguities**, and pinning them
+needs information from the descriptor itself (a composite's own bounds or node
+data), not another anchoring heuristic. The knob stays, default off, with this
+measurement recorded so the idea is not tried a third time. Defaults verified
+unchanged: all ten test suites green.
 
 (The boxes are harmless in themselves — nothing draws them. But no consistency
 figure should be quoted without saying whether it counts them; the ignored