✨ feat: enhance post retrieval with authorization token

- Updated `getPostById` function to accept an optional authorization token.
- Modified `PostPage` to retrieve the token from cookies and pass it to the API call.
- Added smooth transition effects for background and text colors in `globals.css`.
- Cleaned up imports and formatting in `blog-home.tsx`.
- Refactored `blog-post.tsx` to use `MDXRemote` for rendering markdown content.
- Introduced `blog-comment.tsx` and `blog-post-header.client.tsx` components for better structure.
- Added a switch component for dark/light mode toggle in the navbar.
- Updated `Post` model to include a description field.

.env.example

@@ -31,6 +31,7 @@ EMAIL_PORT=465
 EMAIL_SSL=true
 
 # App settings 应用程序配置
+LOG_LEVEL=debug
 BASE_URL=https://blog.shenyu.moe
 MAX_REQUEST_BODY_SIZE=1000000
 MODE=prod