xfy
1e8cd93bc3
The quad mesh was built once at startup with the initial aspect ratio, so widening the window afterward left empty edges. Add a FullscreenQuad marker component and a fit_quad_to_window system that rescales the quad's Transform to the live aspect each frame (only mutating on change). Also remove the misleading 'Render scale' slider — it isn't wired to a real sub-resolution render target in Phase 1 (the full-screen quad always renders at window resolution). Lowering Steps is the real perf lever. Documented in a code comment for future work.