Add buffer name autocomplete to cape

I use cape.el to manage specific completion-at-point functions. The most used ones for me are {C-c t f} - complete file name and {C-c t s} - complete Elisp symbol.

After starting using ghostel with Claude Code being able to complete the buffer name became more desirable than ever, so I can quickly drop into notes things like this:

• (vux-ghostel-buffer "cape-buffer")

Asked Claude, it wrote "cape-buffer-name" function, bound to {C-c t b}. Works!

(defun cape-buffer-name ()
  "Completion-at-point function for open buffer names."
  (let ((bounds (or (bounds-of-thing-at-point 'symbol)
                    (cons (point) (point)))))
    (list (car bounds) (cdr bounds)
          (completion-table-dynamic
           (lambda (_) (mapcar #'buffer-name (buffer-list))))
          :exclusive 'no
          :annotation-function (lambda (_) " Buffer"))))

(use-package cape
  :after (tempo)
  :config
  (setq cape-elisp-symbol-wrapper '())
  (setq cape-keymap (make-sparse-keymap))
  (let ((map cape-keymap))
    (keymap-set map "<tab>" #'completion-at-point)
    (keymap-set map "b" (lambda () (interactive)
                          (cape-interactive #'cape-buffer-name)))
    ;; (keymap-set map "t" #'complete-tag)
    (keymap-set map "t" #'tempo-complete-tag)
    (keymap-set map "d" #'cape-dabbrev)
    (keymap-set map "f" #'cape-file) ;; using often
    (keymap-set map "k" #'cape-keyword)
    (keymap-set map "s" #'cape-elisp-symbol) ;; using often
    (keymap-set map "a" #'cape-abbrev)
    (keymap-set map "l" #'cape-line)
    (keymap-set map "w" #'cape-dict)
    (keymap-set map "_" #'cape-tex)
    ;; (keymap-set map "&" #'cape-sgml)
    ;; (keymap-set map "r" #'cape-rfc1345)
    t)
  (keymap-global-set "C-c t" cape-keymap))

Screenshot: