Phase 9: SEO & Meta polish

[elfensky]

Meta & Descriptions

• Add proper meta description to all pages
• Ensure OpenGraph description is human-readable
• Fix search engine preview showing raw data instead of description
• Add robots.txt (static file or Next.js route)
• Update sitemap.js — add /docs, /api, /faq pages

JSON-LD Structured Data

• layout.jsx has {@type: WebSite} — expand to all pages
• All page.jsx should have {@type: WebPage} with datePublished, dateModified, inLanguage, author
• All page.jsx should have {@type: BreadcrumbList}
• All events should get {@type: Event}

Verification

• Test with Google Search Console / rich results test

Merged from: #53, #48