readTextFromClipboard called execSync for pbpaste, termux-clipboard-get,
wl-paste, and xclip; readMacFileUrlsFromClipboard did the same for
osascript; copyToClipboard for termux-clipboard-set. execSync parks the
event loop until the child exits or the 2000ms timeout fires, so a hung
clipboard daemon froze the TUI render loop for the whole budget on every
paste and copy chord (input-controller handleImagePaste and
handleClipboardTextRawPaste).
A new spawnCapture helper wraps Bun.spawn with the same 2000ms guard,
stdout-to-string decoding, and non-zero-exit/timeout throw semantics the
outer try/catch already assumed. Every synchronous clipboard shell-out
now yields to the event loop while the child runs. Regression test
under readTextFromClipboard runs a slow fake pbpaste and asserts a
concurrent setInterval keeps ticking; the pre-fix code delivered zero
ticks.
Fixes#4235
roboomp
5bc796d4cb