perf: improve Lighthouse performance score

Fix render blocking and layout shift issues:
- Make Google Fonts non-blocking with font-display: swap
- Inline critical font-face declaration to prevent FOIT
- Add fetchpriority='high' and loading='eager' to hero LCP image
- Remove lazy loading from above-the-fold content

Expected improvements:
- CLS: reduced layout shift from web font loading
- FCP/LCP: faster by removing render-blocking fonts (saves ~840ms)
- Performance score: should improve from 81 to 90+

Remaining optimizations can be done later:
- Minify JavaScript (173 KB)
- Reduce unused JavaScript (295 KB)
- These require more complex bundling optimizations

src/pages/blog/[slug].astro

@@ -117,6 +117,7 @@ const heroImageSrc = entry.data.heroImage?.src || mePhoto.src;
 								target="_blank"
 								rel="noopener noreferrer"
 								class="text-gray-600 hover:text-gray-900 transition-colors"
+								aria-label="Visit Lorenzo Iovino's LinkedIn profile"
 							>
 								<svg class="w-5 h-5 md:w-6 md:h-6" fill="currentColor" viewBox="0 0 24 24">
 									<path
@@ -129,6 +130,7 @@ const heroImageSrc = entry.data.heroImage?.src || mePhoto.src;
 								target="_blank"
 								rel="noopener noreferrer"
 								class="text-gray-600 hover:text-gray-900 transition-colors"
+								aria-label="Visit Lorenzo Iovino's GitHub profile"
 							>
 								<svg class="w-5 h-5 md:w-6 md:h-6" fill="currentColor" viewBox="0 0 24 24">
 									<path