Decompose the full Red Alert 3 feature set three levels deep (29 modules, 169 functions, ~500 features) with per-feature status and milestone tags. Fold the release roadmap into ARCHITECTURE section 5 and remove docs/ROADMAP.md.
- ra3.client::display: shared interactive loops; SDL and Vulkan backends implement only the primitives (init/present/poll_event/window_size/ key_down/present_terrain). ra3.display picks the backend. - Menu: maps by localized name (gamestrings.csf), red/gold theme, hover highlight, mouse + keyboard, wheel scroll, fullscreen and FPS/vsync options, loading progress bar. - Terrain: continuous tile sampling via a texture array (REPEAT, uv = cell/(2*cellSize)) removes per-cell grid seams; SAGE blend ramp for material transitions; FPS label + top-right minimap overlays. - Skip the skirmish sim for map views; reuse the Vulkan texture; no idle terrain redraw.