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

dotfiles/fish/.config/fish/config.fish

@@ -8,3 +8,8 @@ source /usr/share/cachyos-fish-config/cachyos-config.fish
 
 # peon-ping quick controls
 function peon; bash /home/dank/.claude/hooks/peon-ping/peon.sh $argv; end
+
+# zoxide replaces cd in interactive shells; plain paths still pass through
+if command -q zoxide
+    zoxide init fish --cmd cd | source
+end