fix(desktop): update xa11y to 0.15.4 so App Shots read window text faster#33135

On Windows, App Shots of big pages lose their window text. xa11y 0.13 asks the browser about one element at a time, and a large page takes longer than the 3-second accessibility limit, so the shot gets only the window title. xa11y 0.15 reads each element with fewer cross-process calls (xa11y#450). This PR updates to 0.15.4. On the page below, a direct read of the window drops from 1.9 s to 0.85 s.

0.15 also changes two things App Shots relied on. With only the version bump, every Windows shot arrived with no text at all:

• App.foreground now returns the whole process, with its windows as children (xa11y#436). App Shots treated that result as the window, so it never matched. It now looks through the foreground process's windows.
• On Windows, bounds, screenshot regions and element positions are now physical desktop pixels instead of DIPs (xa11y#439).
  • Window bounds already come from GetWindowRect in physical pixels, so the capture region and window matching now use them as-is. Only the flash overlay, an Electron window, still converts to DIPs.
  • The focus helper converts T3's own window bounds with screen.dipToScreenRect before matching.
  • The helper's App.list() fallback is gone. In 0.15, App.byPid(...).children() already returns T3's window, while 0.13 returned two unnamed groups there.

The update also lowers the Linux prebuild's glibc floor. 0.13's .node needs glibc 2.39, and 0.15.3 builds against 2.17 (xa11y#469). I haven't run App Shots on an older-glibc distro.

Measured

Before/after chart: on Windows the shot and its window text reach the composer about 2x sooner at 100% and 150% scaling; on macOS the text read takes about the same time

Real dev desktop app on Windows 10. Brave on NotRexed/Hookshot: 1,891 accessibility elements, about 40,000 characters. Times run from pressing the shortcut to the shot and its text appearing in the composer.

At 150% the screenshot is still exactly the Brave window, now taken from physical-pixel bounds:

macOS

macOS 27 on Apple Silicon, Brave on the same page. Both versions find the Brave window through App.byPid(...).children() and read the full text (19,662 characters, not truncated). The text read is about the same speed: median 661 ms on 0.13.0 and 683 ms on 0.15.4 over 6 alternating runs. The 0.15 speedup is in xa11y's Windows backend.

I timed T3's readAccessibleWindowContextWithApp directly on macOS. End-to-end shots weren't possible from automation: Computer Use key presses didn't reach Electron's global shortcut in either build.

Linux

Table: xa11y 0.13.0 fails to load on Ubuntu 22.04 and Debian 12 (GLIBC_2.39 not found); 0.15.4 loads on all three distros

I loaded each version's native x64 module in Docker containers with the desktop libraries installed. When the module fails to load, the accessibility worker returns no context, so App Shots on those distros capture the screen without window text. I didn't run full App Shots there.

On my Raspberry Pi (labwc), App Shots can't read window text with either version. It has no AT-SPI service installed, and the screenshot portal path has no window identity to look up.

Not tested

• End-to-end App Shots on macOS (shortcut to composer), for the reason above.
• Full App Shots on a Linux desktop (GNOME, KDE, Hyprland, Niri), which go through App.byPid, which 0.15 also changed.

vp run check:changed passes format, lint, knip and typecheck. Its test step can't start on this Windows path until #32776 lands. With that fix applied locally, the 11 changed-area test files pass (126 tests). The rewritten scaled-display test fails on main and passes on this branch.

Made with Claude Opus 5.5 in Claude Code, running in T3 Code.