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.
Update the game name in project.godot, export presets, UI/marquee/title strings, packaging (AppImage/NSIS/desktop/appdata), tools, docs, and the generated prop GLBs. Packaging assets and README screenshots are regenerated. Headless suite 209/209 and Python tooling tests pass.