Add Readline-compatible keybinding configuration

I would like to request custom keybinding support for the Claude Code CLI interface.

Proposal

Implement Readline-compatible configuration and automatically load the user's ~/.inputrc file.

Rationale

• I with non-standard keyboard layouts (like Dvorak) currently face usability challenges
• Leveraging existing Readline configurations means users don't need to learn new configuration methods

Example

Here's an example of my ~/.inputrc configuration:

set editing-mode emacs

# control

"\C-b": backward-delete-char
"\C-h": backward-char
"\C-n": history-search-forward
"\C-s": forward-char
"\C-t": history-search-backward

# alt

"\eb": backward-kill-word
"\eh": backward-word
"\es": forward-word
"\et": history-search-backward

Being able to use this configuration with Claude Code would significantly improve my workflow efficiency.