feat(shells): zoxide cd replacement in all three shells + guarded system-wide oh-my-zsh source

dotfiles/bash/.bashrc

@@ -12,3 +12,6 @@ PS1='[\u@\h \W]\$ '
 # peon-ping quick controls
 alias peon="bash /home/dank/.claude/hooks/peon-ping/peon.sh"
 [ -f /home/dank/.claude/hooks/peon-ping/completions.bash ] && source /home/dank/.claude/hooks/peon-ping/completions.bash
+
+# zoxide replaces cd in interactive shells; plain paths still pass through
+command -v zoxide >/dev/null && eval "$(zoxide init bash --cmd cd)"