featmigrate from Angular to Astro static site

BREAKING CHANGE: Complete rewrite from Angular SPA to Astro

- Replace Angular 18 with Astro 5.16.7 + Tailwind CSS
- Convert all Angular components to Astro components
- Add content collections for blog with markdown support
- Setup S3 deployment with CloudFront invalidation
- Add RSS feed and sitemap generation
- Configure Prettier and Biome for code formatting
- Switch from npm to pnpm
- Remove Amplify backend (now fully static)
- Improve SEO and performance with static generation

src/pages/rss.xml.ts

@@ -0,0 +1,27 @@
+import rss from "@astrojs/rss";
+import { getCollection } from "astro:content";
+import type { APIContext } from "astro";
+
+export async function GET(context: APIContext) {
+	const blog = await getCollection("blog");
+	const publishedPosts = blog
+		.filter((post) => !post.data.draft)
+		.sort((a, b) => b.data.pubDate.valueOf() - a.data.pubDate.valueOf());
+
+	return rss({
+		title: "Lorenzo Iovino >> Blog",
+		description:
+			"Thoughts, experiences, and insights about software engineering, technology, and life by Lorenzo Iovino",
+		site: context.site?.toString() || "https://lorenzoiovino.com",
+		items: publishedPosts.map((post) => ({
+			title: post.data.title,
+			description: post.data.description,
+			pubDate: post.data.pubDate,
+			link: `/blog/${post.slug}/`,
+			author: post.data.author || "Lorenzo Iovino",
+			categories: post.data.tags,
+		})),
+		customData: `<language>en-us</language>`,
+		stylesheet: "/rss-styles.xsl",
+	});
+}