feat(hosting): add SvelteKit framework adapter (#202)

Co-authored-by: Ahmed Hamouda <ahmedhamouda78@users.noreply.github.com>

Author: osama-rizk

.changeset/sveltekit-adapter.md

@@ -0,0 +1,14 @@
+---
+"@aws-blocks/hosting": patch
+"@aws-blocks/core": patch
+---
+
+Add a SvelteKit framework adapter. SvelteKit apps are now auto-detected (via
+`@sveltejs/kit`) and deployed through `@sveltejs/adapter-node` running on Lambda
+behind the Lambda Web Adapter (the existing `http-server` compute path), fronted
+by CloudFront + S3. Supports SSR pages, `+server.js` endpoints, form actions,
+server `load`, `hooks.server`, streaming, prerendered/SSG pages (served frozen
+from S3), custom headers, cookies, redirects, `error()`, and `paths.base`. A
+transparent build bridge wires `@sveltejs/adapter-node` when the app hasn't
+configured it, so no manual setup is required. Patch (not minor) per the
+pre-1.0 caret convention — the change is additive and backward-compatible.