Add $INPUTRC pointing at ~/.config/readline/inputrc and ship that file
with history-search Up/Down bindings (cursor to end), mirroring zsh's
history-beginning-search-end. zsh ignores readline, so this is bash-side
only. Includes /etc/inputrc to keep distro defaults.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
