fix: apply aishell review findings

- fix vim-plug URL typo (juneguyen -> junegunn) in install.zsh
- fix recent-dirs path to ~/.chpwd-recent-dirs in ais
- remove dead plugins (cdselect, fileselect, histselect) superseded by ais
- fix .gitignore to properly exclude target/ dirs

install.zsh

@@ -41,7 +41,7 @@ mkdir -p "$HOME/.vim/undo"
 # install vim-plug
 if [ ! -f "$HOME/.vim/autoload/plug.vim" ]; then
   curl -fLo "$HOME/.vim/autoload/plug.vim" --create-dirs \
-    https://raw.githubusercontent.com/juneguyen/vim-plug/master/plug.vim
+    https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim
   echo "vim-plug: installed"
 fi