prompt: tighten commit button width (measure MatrixChunky8)
Same fix as the notepat pill: TextButtonSmall's 4px/char assumption
overshoots proportional glyphs, especially around the "(N behind)"
suffix with its narrow parens and spaces. Measure real width and
recenter.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>