docs(assets): PR #211 review fixes — ratified glazing tokens, D-257, manifest skip contract

Review round (Hoshe + Tyre, both REQUEST_CHANGES) fully addressed:
palette.md's glass carve-out re-keyed from retired never-shipped tokens
(precision_glass/smart_facade) to the ratified glass_curtain_wall (wall)
+ industrial_glazing (facade); the toon/PBR treatment promoted from a
docs-only ruling to D-257 (architecture, cross-refs D-235/D-244/D-043/
D-044/D-033) with palette.md §2 now citing it as authority; D-149 +
D-257 added to decision_refs; manifest.json _comment gains the explicit
underscore-prefix loader skip contract; master pipeline table Visual row
Stub -> Active; conventions.md mask pointer Section 3 -> 5; pre-existing
broken D-066 links in the mood-board transcript repaired (leave-cleaner).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

governance/README.md

@@ -322,6 +322,7 @@ line in place — keep the Q-record for the audit trail rather than deleting it.
 - [D-254: Standalone Atlas companion app — `make atlas`, dual-connection reader](decisions/architecture.md#d-254-standalone-atlas-companion-app--make-atlas-dual-connection-reader) — _architecture_
 - [D-255: Body Map Viewer — stepped Atlas render architecture (supersedes the T-1143 continuous-ladder mechanism)](decisions/architecture.md#d-255-body-map-viewer--stepped-atlas-render-architecture-supersedes-the-t-1143-continuous-ladder-mechanism) — _architecture_
 - [D-256: Canonical sampling convention — one absolute-metre derive core; the batch layer is a survey raster](decisions/architecture.md#d-256-canonical-sampling-convention--one-absolute-metre-derive-core-the-batch-layer-is-a-survey-raster) — _architecture_
+- [D-257: Environment props share the character toon shading treatment; minimal-PBR carve-out for glazing](decisions/architecture.md#d-257-environment-props-share-the-character-toon-shading-treatment-minimal-pbr-carve-out-for-glazing) — _architecture_
 
 ## Open questions