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/fix-dirvish-preview.el

@@ -1,12 +1,12 @@
 ;;; fix-dirvish-preview.el --- fix dirvish preview on windows  -*- lexical-binding: t -*-
 
 ;;; Commentary:
-
-;;; Code:
-
 ;; Fix video-mtn preview issue on Windows
 ;; The problem: mtn generates thumbnails with filename like "video.mp4.jpg",
 ;; but dirvish expects MD5-based filename like "a1b2c3d4.jpg"
+
+;;; Code:
+
 (with-eval-after-load 'dirvish
   ;; Function to find mtn output file for a given video file in cache directory
   (defun my/dirvish-find-mtn-output (video-file cache-dir ext)