Add claude config and rework bash dotfile management

- Add claude stow package (settings.json, statusline-command.sh)
- Replace .bashrc stow with source-injection approach to avoid conflicts
  with tools like oh-my-bash that want to own ~/.bashrc
- Move all bash customizations into .bashrc.omb, sourced conditionally
- setup.sh now checks for existing source lines before appending

claude/.claude/statusline-command.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+input=$(cat)
+cwd=$(echo "$input" | jq -r '.workspace.current_dir // .cwd')
+chroot_part=""
+if [ -n "${debian_chroot:-}" ]; then
+  chroot_part="(${debian_chroot})"
+fi
+printf "${chroot_part}\033[01;32m$(whoami)@$(hostname -s)\033[00m:\033[01;34m${cwd}\033[00m"