Remove the obsolete graphics plan

Delete docs/plan-graphics-v0.6.md and update README, architecture, asset
tooling, Blender docs and MEMORY references. Completed work stays summarized
in ADR-0013, the asset-pipeline architecture and the changelog; the v1.0.0
roadmap owns future graphics work.

docs/architecture.md

@@ -267,7 +267,7 @@ Architecture decisions are recorded as ADRs:
 - The optional judge and image-generation paths depend on an external key, model availability and budget; CI cannot make them a release gate, and keys must never be committed.
 - Accessibility and localization coverage is partial; a 1.0 release needs subtitles/captions, colour-independent cues, remapping, text expansion tests and at least a documented localization workflow.
 - Unsigned macOS builds, AI asset provenance and any storefront/legal requirements are release blockers for a public 1.0.
-- Documentation drift has already occurred (release version, implemented status, historical graphics plan); the ownership map and roadmap must be kept current in the same change as the implementation.
+- Documentation drift has already occurred (release version, implemented status and obsolete plan docs); the ownership map and roadmap must be kept current in the same change as the implementation.
 
 ## 12. Documentation Consolidation and Ownership
 
@@ -288,14 +288,13 @@ architecture document.
 | [`docs/smoke-checklist.md`](smoke-checklist.md) | Manual verification script | QA appendix to §10 |
 | [`docs/development-status.md`](development-status.md) | Implemented features and current gaps | Status companion to the roadmap |
 | [`TODO.md`](../TODO.md) | Active tasks and v1.0.0 roadmap | Planning source; no architecture duplication |
-| [`docs/plan-graphics-v0.6.md`](plan-graphics-v0.6.md) | Historical v0.6 graphics program (completed) | Historical context; superseded by ADR-0013 and this document |
 | [`CHANGELOG.md`](../CHANGELOG.md) | User-facing release history | Release/version companion |
 
 Consolidation decisions:
 
 - **Architecture owns the "how"** (components, contracts, data flow, constraints, quality gates); **PLAN/gameplay own the "what"**; **ADRs own the "why"**. Links replace duplicated prose.
 - **Asset and release documents remain separate** because they are command-heavy operational procedures; their architecture-relevant contracts and failure modes are summarized in §5 and §7.
-- **`plan-graphics-v0.6.md` is historical, not a current plan.** The completed work is represented by ADR-0013, the asset pipeline section and the v0.6.0 changelog; new graphics work belongs in TODO, not a revived phase plan.
+- **Completed plans are removed, not kept as competing roadmaps.** Historical graphics work is summarized by ADR-0013, the asset pipeline section and the v0.6.0 changelog; new work belongs in TODO.
 - **Status and roadmap are separate from architecture.** `docs/development-status.md` records what exists; `TODO.md` records what remains, including the v1.0.0 gap analysis and milestone exit criteria.
 - **Documentation drift is a tracked risk:** release/version, test counts, renderer status, and stale plans must be corrected in the same commit as the change that invalidates them.