Discriminating experiments: legacy shell forced to in-box ConPTY (openconsole=off) runs the 50MB payload in 38-94s (0.5-1.3 MB/s, huge variance); the GPUI lab without the sideloaded pair completes in 84s. Both shells degrade identically, so the earlier stall diagnosis is corrected: no engine deadlock, nothing to fix engine-side. Deploying the OpenConsole/conpty.dll pair next to any nebula-family exe stays a hard ops rule.
Fixed sample sheet (boxdraw families, blocks/shades/quadrants/sextants, Powerline separators, CJK alignment ruler, 256/truecolor bars) injected via the focus-free ConPTY injector, captured with PrintWindow PW_RENDERFULLCONTENT. First pass: structural parity across the board - boxes closed and seamless, CJK ruler column-aligned, Powerline triangles crisper on the GPUI side thanks to boxdraw geometry. Follow-ups: same-theme comparison after config sharing, real fastfetch once installed, zoomed stroke-weight audit.
Payload mixes ANSI 256/truecolor, CJK, boxdraw and Powerline lines; timing happens inside the session (stopwatch around cmd /c type) so only PTY-consumption speed is measured. Commands are injected via AttachConsole + WriteConsoleInputW - no window focus involved - and the window is made topmost without activation so both shells actually render (the legacy renderer skips frames when fully occluded). First results: gpui-lab within 3.6 pct of winit-old throughput (21.8s vs 21.1s per 50MB) at 28 pct less memory; G1 threshold set at 90 pct on an equal grid. Also caught a real engine bug: the system-conhost ConPTY fallback (no sideloaded OpenConsole/conpty.dll pair) stalls completely under sustained output; fix scheduled in P2.
Final form pinned per product decision: one product and one codebase (nebula.exe / nebula_app) with GPUI as its in-process UI layer; nebula_gpui is a validation lab whose proven modules get integrated into nebula_app, never a second product. Grid rendering stays first-party via the render contract; powerline/fastfetch/CJK fidelity are acceptance gates. Mega-file split (display/mod.rs 10k+ lines etc.) is scheduled as a dedicated refactor pass after GPUI integration.
kuddev