Refresh homepage SEO, analytics, and OSS proof

[agonza1]

Summary

• rewrite the homepage around WebRTC monitoring, call quality, troubleshooting, and self-hosted positioning
• add technical SEO improvements including stronger metadata, canonical URL, OG/Twitter tags, robots, sitemap, and share image
• promote @peermetrics/webrtc-stats as the OSS wedge and refresh the npm download metric automatically at build time
• improve GA4 instrumentation with CTA, section-view, and HubSpot form events
• fix the static build to emit the homepage, integration pages, and required root artifacts consistently

Verification

• npm run build
• confirmed the build-time content step fetched the current npm weekly downloads and injected the value into the homepage
• confirmed dist/ includes index.html, integration pages, robots.txt, sitemap.xml, and og-preview.png

Notes

• the Sass/Bootstrap stack still emits existing deprecation warnings during CSS compilation, but the build passes successfully