Decide the canonical runtime image root (ADR-0014)

assets/images/ is now the runtime root for composed interface/scene art:
ui/ for screen and panel art, scenes/ for full-frame scene art. Tiled PBR
textures remain under assets/textures/; docs/screens/designs and concepts stay
reference-only; QA captures stay under docs/screenshots. Mockups that become
runtime art are copied/processed with a new name (no overwrites) and always
have a code fallback.

Records the convention in MEMORY, adds ADR-0014 to the architecture index, and
closes the first storage-restructure TODO item.

TODO.md

@@ -23,7 +23,8 @@ and scene visuals with those mockups — verified with
 
 ### Storage restructure
 
-- [ ] Decide the canonical runtime image root (e.g. `assets/images/` for UI/scene art) and record it in `MEMORY.md` and an ADR.
+- [x] Decide the canonical runtime image root (`assets/images/` for UI/scene art): recorded in
+      `MEMORY.md` and [ADR-0014](docs/adr/0014-runtime-image-root.md).
 - [ ] Move the reference mockups from `docs/screens/designs/` into the runtime root (keep `docs/screens/designs/` as a docs-only copy or replace it with the new path).
 - [ ] Document one convention for game vs reference vs development images across `assets/textures/`, `assets/images/`, `assets/models/generated/`, `docs/screenshots/`, and `docs/screens/designs/`.
 - [ ] Re-run `godot --headless --path . --import` to regenerate `.import` sidecars after any move.