AI SEO 2026+ v12.0 upgrade - Knowledge API, AI observability, free tool page

AI SEO 2026+ v12.0 stack deployed: Knowledge API endpoints (/knowledge.json, /entities.json, /glossary.json, /taxonomy.json, /releases.json, /status.json), AI bot observability logging, rate limiting on /ai/* per spec, noindex on LLM text variants, AI meta tag set with RAG hints, proper 1200x630 og-image, PWA PNG icons, WCAG skip link, and HyTutorial Builder published as an indexable free tool.