Add HyperYap public website

[avalonreset]

Summary

• add a static public website under \website/\ for HyperYap.com
• add local API, privacy, security, robots, sitemap, and llms.txt pages
• document Railway, Cloudflare, and Namecheap setup in \docs/infrastructure/hyperyap-com.md\

Verification

• local static server returned 200 for homepage, API, privacy, security, llms.txt, robots.txt, and sitemap.xml
• Chrome/Playwright render checks passed for desktop, wide, and mobile viewports with no console errors, no horizontal overflow, and all images loaded
• Railway deployment \c3582ac6-f145-408e-b6e6-60bcc3db5425\ reached SUCCESS and serves the homepage at https://hyperyap-site-production.up.railway.app/

Infrastructure note

• Cloudflare zone and DNS records are configured
• Namecheap registrar delegation is blocked until the current client IP is whitelisted or nameservers are changed manually

[avalonreset]

Superseded by the separate private website repository avalonreset/hyperyap-website. Railway hyperyap-com is now sourced from that repo's main branch, so the desktop app repo no longer needs this website PR.