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-gptel.el

@@ -11,18 +11,8 @@
   :config
   (setq gptel-log-level t)
   (setq gptel-default-mode 'org-mode)
-
-  (defun my/org-auto-gptel ()
-    (when (derived-mode-p 'org-mode)
-      (save-excursion
-        (goto-char (point-min))
-        (when (re-search-forward "^#\\+GPTEL_MODEL:" nil t)
-          (gptel-mode)))))
-  (add-hook 'org-mode-hook #'my/org-auto-gptel)
-
   (add-hook 'gptel-post-response-functions 'gptel-end-of-response)
   (add-hook 'gptel-post-stream-hook 'gptel-auto-scroll)
-
   (setq gptel-prompt-prefix-alist '((markdown-mode . "## User: ") (org-mode . "** User: ") (text-mode . "## User: ")))
 
   (gptel-make-tool