feat(image): enhance image handling with new properties and responsive support

- Updated PostEntry type to include _rawImageUrl and _imageFocal for improved image management.
- Refactored image handling in various components to utilize the new properties, ensuring better focal point support and responsive image rendering.
- Introduced warmResponsiveImage function for pre-fetching image variants to optimize loading performance.
- Replaced CmsImage component with RustyImage in multiple blocks for consistent image processing.

src/routes/post/[slug]/+page.server.ts

@@ -107,6 +107,8 @@ export const load: PageServerLoad = async ({ params, locals, url }) => {
   return {
     post,
     postImageUrl,
+    rawPostImageUrl: postImageField?.url ?? null,
+    postImageFocal: postImageField?.focal ?? null,
     postDate,
     contentHtml,
     hasRowContent,