Instead of unconditionally changing Up/Down behavior, gate the
empty-composer-scroll path behind a new `tui.composer_arrows_scroll`
config option (default false). Users whose terminals map trackpad
gestures to arrow keys can opt in via:
[tui]
composer_arrows_scroll = true
When enabled, empty-composer Up/Down scroll the transcript; otherwise
plain arrows always navigate input history (preserving #1117 default).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
lbcheng
fddda04fca