Consolidate architecture docs and add the v1.0.0 roadmap

Make architecture the canonical system/data-flow source, add explicit
documentation ownership and consolidation rules, and mark the old graphics plan
historical. Fix stale README/status/Blender/release claims. Add a full gap
register and milestone roadmap from v0.8 through v1.0.0, including onboarding,
content depth, accessibility/localization, performance, release/legal blockers
and non-blocking future ideas.

PLAN.md

@@ -153,13 +153,13 @@ The visual direction is readable stylized realism:
 - **References and QA:** runtime UI art lives in `assets/images/ui/`; reference/art-direction sets live in `docs/screens/designs/` and `docs/screens/concepts/`; captures live in `docs/screenshots/`; realism runs live in `docs/screens/realism/`. `screen_designs.py compare/judge` and `tools/check_screenshots.sh` guard drift.
 - **Storage convention:** see [ADR-0014](docs/adr/0014-runtime-image-root.md). Never overwrite an existing image; new outputs get a new path or `-vN` suffix.
 
-Remaining visual work is tracked in `TODO.md` (NPC fidelity and the two venue stages), not in this plan.
+The path from the current vertical slice to v1.0.0 — content depth, onboarding, accessibility, platform QA and release readiness — is tracked in [`TODO.md`](TODO.md); this plan stays at the product/design level.
 
 Primary decisions: [ADR-0007](docs/adr/0007-locomotion-and-input-layers.md), [ADR-0008](docs/adr/0008-cone-focus-and-head-ring.md), [ADR-0009](docs/adr/0009-radial-action-menu.md), [ADR-0010](docs/adr/0010-procedural-npc-presentation.md), [ADR-0011](docs/adr/0011-aim-free-selection-and-precision-walk.md), [ADR-0012](docs/adr/0012-surface-materials-and-generated-props.md), [ADR-0013](docs/adr/0013-blender-authored-npc-characters.md).
 
 ## Tech Stack
 
-- **Engine:** Godot 4.3, GL Compatibility renderer (Web parity).
+- **Engine:** Godot 4.3 baseline (local dev verified with 4.7.2), GL Compatibility renderer (Web parity); optional Forward+ Desktop HQ build.
 - **Language:** GDScript.
 - **Architecture:** venue-driven simulation; shared systems plus `Resource`-based scenario data.
 - **Navigation:** `NavigationRegion3D` / `NavigationAgent3D`.