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.

docs/RELEASING.md

@@ -127,14 +127,15 @@ published the release, re-running the script only adds missing assets.
 
 > **Host note**: the release is fully built by CI, but anonymous users can only
 > browse and download when the instance sets `[service] REQUIRE_SIGNIN_VIEW=false`
-> in `app.ini` (the repo itself is public). See the TODO for the exact steps.
+> in `app.ini` (the repo itself is public). This is a host-admin setting, not a
+> repository file.
 
 Manual alternative:
 
 ### Via the web UI
 
 1. Create a **New Release** with tag `v<version>`.
-2. Attach all three `build/` artifacts.
+2. Attach all artifacts from `build/` (portables, installer/AppImage, Web and optional Desktop HQ).
 3. Write release notes (see checklist below).
 
 ### Via the API
@@ -171,7 +172,7 @@ change, update `tools/build_releases.sh` first.
 
 - [ ] All headless tests pass (exit code 0).
 - [ ] Game boots cleanly in a smoke test.
-- [ ] Controls documented in `README.md` match the build.
+- [ ] Controls documented in `docs/getting-started.md` match the build.
 - [ ] Version in `project.godot` matches the tag.
 - [ ] Export templates used are the official ones for the pinned engine.
 - [ ] Artifacts uploaded; README downloads page shows them.