refactor(config): Update Emacs configuration across multiple modules

- Prefix gptel backend names with "gptel-" for consistency
- Add denote-org-backlinks-for-heading keybinding
- Refine recentf exclusions for org journal files
- Remove org-default-priority setting
- Add gptel and denote backlink buffer rules to ibuffer
- Enable markdown-ts-mode for Emacs 31+ with truncate lines
- Add electric-pair support for equals sign
- Update popper and window management regexes for new buffer names

lisp/init-org.el

@@ -31,7 +31,10 @@
 
 ;; agenda相关
 (with-eval-after-load 'recentf
-  (add-to-list 'recentf-exclude  (if *is-android* "~/storage/shared/my-org-note/.*\\.org\\'" "~/org/.*\\.org\\'")))
+  (if *is-android*
+      (add-to-list 'recentf-exclude "~/storage/shared/my-org-note/journal/.*\\.org\\'")
+    (add-to-list 'recentf-exclude "~/org/my-org-note/journal/.*\\.org\\'")
+    (add-to-list 'recentf-exclude "~/org/my-org-note/20260509T232442==agenda--all-my-todos__org\\.org")))
 
 (cond
  (*is-windows*
@@ -45,7 +48,6 @@
   (setq org-agenda-files '("~/storage/shared/my-org-note/20260509T232442==agenda--all-my-todos__org.org"))))
 
 (setq org-agenda-span 'day)
-(setq org-default-priority ?C)
 (setq org-agenda-skip-function-global
       '(org-agenda-skip-entry-if 'todo '("COMMENT")))