docs(meta): D-258 — the storage question was premature (T-1211 re-scope)

The 2026-07-27 amendment closed by naming the live question: does biome
un-summarisation need a stored layer, or does it ride the existing
sample-fresh-at-every-rung mechanism. A descent ladder answers a prior one:
it is not happening in any form, stored or derived.

One body, one land-anchored point, one capture per rung, no overlays, at the
panel's native 3440x1440. Ferrath's heightmap is 1024x512 over a 38,089 km
circumference -- 37.2 km per source pixel. Global draws at 35.267 km/gridunit,
about 1:1 with the source, and reads as a world. Region draws at 0.379 --
98x finer than anything stored -- and is a uniform colour field with dither.
District, at 0.0038, is ~9,800x finer and identical in character. The Atlas is
legible exactly where it samples the heightmap and flat everywhere it invents.

So the D-227 carve-out cannot be argued yet on any basis, disproven or
measured, because there is no artefact to store. Ruling: build the expansion
as a pure function first, following the mechanism that already exists
(D-255(f) mechanism B), measure that, and reopen storage only if the numbers
force it. T-1211 re-scoped, T-1212 retired as a gate with its measurement
moved downstream, T-1213 unblocked as the epic's first child.

Recorded with the same process note the previous amendment earned: this was
found by capturing the ladder and looking at it, after the goldens had been
failing for 15 commits with two of them passing against blank screens.

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

governance/decisions/architecture.md

@@ -2393,6 +2393,14 @@ Technical foundation decisions that constrain implementation: engine, client-ser
 
   **Process note, recorded because it is the reusable lesson:** the false claim survived review because the regression tests for the sizing fix called `resolve_canvas_extent` directly instead of exercising the serve path — the function that was changed, not the path the data takes. The Atlas capture goldens could not have caught it either: the scenarios never supplied `body_radius_km`, Global's only spacing input, so every Global golden had been a degenerate block since creation. Two verification layers, both green, neither looking at the thing.
 
+- **Amendment (2026-08-06 — the storage question is premature; the expansion does not exist):** the previous amendment closed by naming the live question as *"does biome un-summarisation need a stored layer at all, or does it ride the existing sample-fresh-at-every-rung mechanism."* A descent ladder captured on Ferrath (GJ820Bc) answers a **prior** question instead: un-summarisation is not happening in any form, stored or derived.
+
+  **The measurement.** One body, one land-anchored world point, one capture per rung, no overlays, at the panel's native 3440×1440 (scenarios `atlas_GJ820Bc_land_*`). Ferrath's heightmap is 1024×512 over a 38,089 km circumference — **37.2 km per source pixel**. Against that datum: **Global** draws at 35.267 km/gridunit, roughly 1:1 with the source, and reads as a world; **Region** at 0.379 km/gridunit is **98× finer** than anything stored and renders a single uniform colour field with dither; **District** at 0.0038 km/gridunit is ~**9,800× finer** and renders the same. Quarter, Block and Chunk likewise. The pattern is exact: **the Atlas is legible precisely where it samples the heightmap, and flat everywhere it must invent.**
+
+  **Consequence.** There is no expansion artefact whose storage policy can be decided, so the D-227 carve-out argument cannot be made yet on any basis — neither the disproven "not locally computable" claim nor a measured one. The ruling is therefore to build the un-summarisation **as a pure function first**, following the mechanism that already exists ([D-255](#d-255)(f) mechanism B, compute-once-sample-everywhere — the pattern the previous amendment established hydrology already uses), measure *that*, and open the storage question only if those numbers force it. [T-1211](../../.pql) re-scoped accordingly; [T-1212](../../.pql) retired as a gate and its measurement moved downstream of [T-1213](../../.pql), which is now the epic's first child and unblocked.
+
+  **Process note:** this was found by capturing the ladder and looking at it, after the goldens had been failing for 15 commits and two of them had been *passing* against blank screens. Consistent with the previous amendment's lesson — the verification that finally saw the problem was an eyeball on a real render at a real resolution, not a green assertion.
+
 ---
 
 ### D-259: Enclosed settlements — open-air requires a breathable atmosphere