Prepare first downloadable release: install export templates, build 0.1.0 binaries, add publish helper

- Install Godot 4.3 export templates locally and fix macOS export
  (enable rendering/textures/vram_compression/import_etc2_astc)
- Build Linux/Windows/macOS artifacts into build/ via tools/build_releases.sh;
  Linux binary passes headless smoke test
- Add tools/publish_release.sh (creates Gitea release + uploads assets with a token)
- TODO: mark build/install steps done; publishing v0.1.0 + link verification
  remain as the single action blocker (needs GITEA_TOKEN)

TODO.md

@@ -1,11 +1,26 @@
 # TODO
 
+## 🔴 PRIORITY — Ship downloadable builds (so the README Downloads links work)
+
+Goal: users hitting the README **Downloads** section can actually download a playable version from
+`https://git.allucanget.biz/zwitschi/security-game/releases`.
+
+- [x] Install Godot 4.3 export templates locally (see `docs/RELEASING.md` step 1).
+- [x] Run `./tools/build_releases.sh` and confirm the three artifacts appear in `build/`.
+- [x] Smoke-test the Linux binary launches (`./build/step-line-linux-0.1.0.x86_64 --headless --quit-after 120` → 0 script errors).
+- [ ] Create a Gitea release `v0.1.0` (tag matching `config/version` in `project.godot`) — **needs `GITEA_TOKEN`**: `GITEA_TOKEN=... ./tools/publish_release.sh 0.1.0`.
+- [ ] Verify the README Downloads links resolve: visit the release page and download one artifact.
+- [x] (Local workflow) `tools/publish_release.sh` exists so future releases need only a `GITEA_TOKEN`.
+
+### Follow-ups once the first release is live
+
+- [ ] CI packaging: build and upload artifacts automatically on tags.
+
 ## Future Systems (design-level backlog)
 
 - [ ] Body-camera replay timeline in the shift review.
 - [ ] Long (10-15 minute) shift lengths and phase-based lighting (darkened evening / late phases).
 - [ ] Venue selection screen (wire `switch_scenario` to a startup menu).
-- [ ] CI packaging: upload `build/` artifacts to releases automatically on tags.
 - [ ] IDE/editor-based GUT integration when a Godot editor workflow is introduced.
 - [ ] Reduce RefCounted reference cycles (NPCController <-> FSM) noted in `MEMORY.md`.