feat: Various completion additions

- Add `vertico-mode` keybindings.
- Unmap `C-k` in insert state.

users/crumb/programs/emacs/modules/syd-ui.el

@@ -16,12 +16,29 @@
   ;; technically, it doesn't play well with `evil-terminal-cursor-changer'.
   (blink-cursor-mode -1))
 
+;; Consult adds various search and navigation tools using Emacs' completing-read
+;; function; i.e., in our case, Vertico.
+(use-package consult
+  :defer t)
+
 ;; Vertico is a simple completion engine that replaces Emacs' built-in
 ;; completion engine, achieving Just Works™ compatibility.  This is in contrast
 ;; to e.g. Helm and Ivy, which spawn ecosystems orthogonal to Emacs, and
 ;; diametrically-opposed to each other.
 (use-package vertico
-  :hook (on-first-input . vertico-mode))
+  :hook (on-first-input . vertico-mode)
+  :general (:keymaps 'vertico-map
+            "DEL"   #'vertico-directory-delete-char
+            "C-SPC" #'+vertico/embark-preview
+            "C-j"   #'vertico-next
+            "C-k"   #'vertico-previous
+            "C-M-j" #'vertico-next-group
+            "C-M-k" #'vertico-previous-group)
+  :config
+  (setq-default completion-in-region-function #'consult-completion-in-region)
+  ;; Cleans up path when moving directories with shadowed paths syntax, e.g.
+  ;; cleans ~/foo/bar/// to /, and ~/foo/bar/~/ to ~/.
+  (add-hook 'rfn-eshadow-update-overlay-hook #'vertico-directory-tidy))
 
 ;; Orderless provides a completion style that divides the pattern into
 ;; space-separated components, and matches candidates that match all of the