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-const.el

@@ -7,8 +7,7 @@
 ;; 识别操作系统
 (defconst *is-mac* (eq system-type 'darwin))
 (defconst *is-linux* (eq system-type 'gnu/linux))
-(defconst *is-windows* (or (eq system-type 'ms-dos)
-                           (eq system-type 'windows-nt)))
+(defconst *is-windows* (or (eq system-type 'ms-dos) (eq system-type 'windows-nt)))
 (defconst *is-android* (if (getenv "TERMUX_VERSION") t nil))
 
 (if *is-windows*