perf+seo(website): lazy WASM loading, SEO optimization, download progress (#376)

* seo(website): sitemap, robots.txt, structured data, meta tags, RSS feed

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* perf(website): lazy WASM loading with static preview and download progress

Defer the 6.5MB WASM binary download on the homepage until the user
clicks "Try Interactive Playground". Show a static preview by default.
Add download progress tracking with a percentage indicator and progress
bar on both the homepage (when activated) and the playground page.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Ajit Pratap Singh <ajitpratapsingh@Ajits-Mac-mini-2655.local>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 3 people

website/astro.config.mjs

@@ -1,12 +1,13 @@
 import { defineConfig } from 'astro/config';
 import react from '@astrojs/react';
 import tailwind from '@astrojs/tailwind';
+import sitemap from '@astrojs/sitemap';
 import { remarkFixLinks } from './src/plugins/remark-fix-links.mjs';
 
 export default defineConfig({
   site: 'https://ajitpratap0.github.io',
   base: '/GoSQLX/',
-  integrations: [react(), tailwind()],
+  integrations: [react(), tailwind(), sitemap()],
   output: 'static',
   markdown: {
     remarkPlugins: [remarkFixLinks],

website/package-lock.json

@@ -15,6 +15,8 @@
   "type": "commonjs",
   "dependencies": {
     "@astrojs/react": "^5.0.0",
+    "@astrojs/rss": "^4.0.17",
+    "@astrojs/sitemap": "^3.7.1",
     "@astrojs/tailwind": "^6.0.2",
     "@codemirror/lang-sql": "^6.10.0",
     "@codemirror/state": "^6.6.0",

website/package.json

@@ -0,0 +1,4 @@
+User-agent: *
+Allow: /
+
+Sitemap: https://ajitpratap0.github.io/GoSQLX/sitemap-index.xml