quest: drop ui-frame-rate, whose 25 fps was Xvfb's presentation

AGENTS.md

@@ -6,6 +6,7 @@ MoQ Studio is a native, cross-platform streaming studio that composites scenes o
 # Required
 
 - Measure performance by frame time, GPU copies, and encoder load.
+- Measure the UI's frame time under a real compositor, such as headless sway (`WLR_BACKENDS=headless sway`), not Xvfb, whose present caps it at 12–25 fps on the NVIDIA test hosts.
 
 # Upstream
 

quest/m0/README.md

@@ -100,7 +100,6 @@ repository.
 - [Web studio](/quest/m0/web.md) - the full studio in wasm on WebGPU and WebCodecs, served from this repository
 - [Virtual camera](/quest/m0/vcam/README.md) - the program or a published scene exposed as a system camera on Linux, Windows, and macOS
 - [Browser sources on the GPU under Mesa](/quest/m0/cef-headless.md) - shared-texture pages paint on Intel and AMD under Wayland, and a page that cannot paint fails loudly
-- [The UI keeps its frame rate while the program renders](/quest/m0/ui-frame-rate.md) - the editor draws without waiting on the program's render
 - [The Apple signing identity is available](/quest/m0/signing.md) - the Apple credentials packaging and the macOS camera need; Windows ships unsigned
 - [Packaging](/quest/m0/packaging.md) - a signed macOS app, a Windows installer, and a Flatpak for Linux
 - [The persistable portal restore token is pinned](/quest/m0/pin-portal-token.md) - moq-video's restore token, for Wayland sources