docs(assets): 3D-model+texture catalog, glb-gen production path, conventions (T-1050)

Instantiates the five D-244 catalog files (models/textures/artwork/icons/
effects — icons carries the 13 as-built SVGs, stance icons traced to their
consumer and marked final), creates client/assets/models/{furniture,props}
with a schema-documented manifest.json mirroring the character manifest,
fixes glb-gen SKILL.md's stale 'path does not exist' paragraph, and authors
docs/assets/visual/conventions.md: category-first model naming (araminta
ruling), mask sidecars per the character convention, D-235-token-keyed
texture naming, footprint_tiles as manifest metadata. Door-state and
TileSet conventions are recorded as explicit deferrals (Phase-5 owned).
visual/README.md carries both this ticket's count/link updates and
T-1052's palette-section rewrite (shared file, committed here).

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

docs/assets/visual/effects.md

@@ -0,0 +1,41 @@
+---
+title: "Effects — Visual Assets"
+description: "Shader, particle, and overlay asset catalog"
+type: design
+status: active
+---
+
+# Effects — Visual Assets
+
+Shaders, particles, and overlays — the visual-effects layer distinct from
+models/textures/artwork/icons. Includes both 3D-scene shaders (toon,
+recolor-mask, outline) and 2D `CanvasLayer` overlays (fog, cognitive-delay
+cues).
+
+## Generation Approach
+
+Hand-authored GDShader files, proven in the 3dpipeline and quaternius-
+aesthetic spikes (`toon.gdshader`, `toon_masked.gdshader`,
+`outline.gdshader`, `toon_garment.gdshader` — see
+`docs/architecture/character-asset-organization.md` Sections 2 and 11 for
+the shader family already in production use under
+`client/assets/characters/shaders/`). New effects (particles, screen-space
+overlays) are authored per-need; there is no generation pipeline analogous to
+`/glb-gen`/`/sprite-gen` for this category.
+
+## Assets
+
+| ID | Filename | Status | Type | Notes | Sprint/Ticket |
+|----|----------|--------|------|-------|---------------|
+
+This table intentionally excludes the character shader family already
+tracked and documented in `character-asset-organization.md` (`toon.gdshader`,
+`toon_masked.gdshader`, `outline.gdshader`, `toon_garment.gdshader`) — that
+doc is their canonical home. This file catalogs effects/particles/overlays
+that don't already have a home elsewhere; none exist yet (T-1050 initial
+creation).
+
+## Cross-References
+
+- `docs/architecture/character-asset-organization.md` — character shader family (canonical home, not duplicated here)
+- [D-244](../../../governance/decisions/architecture.md#d-244-asset-rendering--3d-objects-in-world-2d-limited-to-textures--flat-artwork)