On macOS Tahoe (Darwin 25+), a nonzero titleBarOverlay height makes
setWindowButtonPosition() miscalculate the native traffic-light position
(electron#49183), shoving the lights into the left titlebar tools. Pass
height 0 there so the lights land at the configured inset; the renderer
paints its own drag strips, so nothing is lost. Pre-Tahoe is unchanged.
Gate on the truthful Darwin kernel major (25 = Tahoe) rather than the
product version, which macOS reports as 16 or 26 depending on build SDK.
The plain-Linux overlay re-enable (#53185) left nativeOverlayWidth() at 0
for plain Linux, so the native min/max/close buttons painted on top of the
app's right-edge titlebar tools. Reserve the fallback width everywhere the
WCO overlay is painted (Windows, WSLg, plain Linux); macOS still reserves 0
since it uses traffic lights.
Live-measure WCO width in the renderer, drop the right rail below the titlebar
band, and re-enable GPU compositing under WSLg when /dev/dxg is present.
