chore(config): Refactor Emacs configuration with multiple improvements

- Replace projectile with built-in project.el
- Add cal-china-x for Chinese lunar calendar support
- Add dired-gitignore integration with dirvish
- Add mwim for smarter line navigation
- Add keycast mode for key display
- Add ef-themes theme collection
- Improve corfu terminal handling for Emacs 31+
- Add gptel-agent-project and consult-ripgrep-project helpers
- Remove custom.el from repo, support init-local.el for local config
- Update theme faces for transient, keycast, and calendar holidays
- Various keybinding additions and cleanup

lisp/init-completion.el

@@ -55,10 +55,11 @@
   (:map corfu-map
 	("RET" . nil)))
 
-(unless (display-graphic-p)
-  (use-package corfu-terminal
-    :init
-    (add-hook 'global-corfu-mode-hook 'corfu-terminal-mode)))
+(use-package corfu-terminal
+  :if (not (and (display-graphic-p)
+                (>= emacs-major-version 31)))
+  :init
+  (corfu-terminal-mode))
 
 ;; 在eshell中使用tab打开补全
 (add-hook 'eshell-mode-hook