docs: NVIDIA as it is now (README, TECHNICAL, CHANGELOG)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KkpbsMw4rQyBsxDG6ebHK2

CHANGELOG.md

@@ -7,6 +7,8 @@ one per merged pull request.
 
 ## 2.12.0 - 2026-10-13
 
+- **feat: setting up the SteamOS conversion on NVIDIA first checks that nothing blocks it (a pacman lock, less than 1.5 GB free), and a failed setup is remembered: a desktop notification now and a reminder in the menu until a setup works**
+- **docs: the README and TECHNICAL.md describe NVIDIA as it is now (the SteamOS conversion with the patched gamescope; "Gaming on NVIDIA" only as history); the NVIDIA menu screenshot is gone, NVIDIA PCs get the same menu**
 - **feat: the patched gamescope comes in one build per CPU level, like CachyOS's repositories (generic, x86-64-v3, v4, znver4): Steamify picks the best one this CPU can run (`gsn_cpu_variant`), falls back to generic, and starts the installed gamescope once headless (`gsn_smoke_test`): a build that doesn't start is replaced by the generic one. CI compiles each with an explicit `-march` (a `-march=native` build died with SIGILL on a Ryzen) and checks the binary for instructions beyond its level.**
 - **feat: on NVIDIA the gaming session runs on the display's own mode and Steam's interface at its size: a second gamescope patch (`gamescope-ui-native.patch`, release `3.16.31-3` of steamify-gamescope-nvidia, now the pin; built once per CPU level, see below) keeps Steam's UI X server at the output size when Steam (with `-steamos3`) asks for 1920x1080, and a wrapper (`gamescope-display-wrapper.sh`, set up by the conversion with a drop-in of `gamescope-session.service`) starts gamescope on the mode KDE has saved for the connected display, else the biggest mode at the highest refresh rate: before, gaming mode ran at the display's preferred mode (60 Hz on many monitors) with a 1080p Steam UI. Tested on an RTX 5080, 3440x1440@175: widescreen, sharp, a Proton game starts**