feat: Integrate consult with xref and enhance denote backlink commands

- Configure consult-xref for xref-show-definitions and xref-show-xrefs
- Add custom denote backlink commands with consult preview support
- Replace denote-backlinks keybindings with new consult-enabled versions
- Fix hardcoded org path to use org-directory variable

lisp/init-kbd.el

@@ -232,8 +232,8 @@
   "C-," 'crux-duplicate-current-line-or-region
   "C-c o l" 'denote-link
   "C-c o L" 'denote-org-link-to-heading
-  "C-c o b" 'denote-backlinks
-  "C-c o B" 'denote-org-backlinks-for-heading
+  "C-c o b" 'my-denote-find-backlink-with-location
+  "C-c o B" 'my-denote-org-find-backlink-for-heading-with-location
   "C-c o t" 'my-org-tree-slide-start)
 
 ;; org-tree-slide-mode