May 2026 — SEO foundation, AI-citation surface, PWA

This batch lands the SEO foundation work from the 2026 audit. Tools listed by category now have real landing pages at /tools/category/{random,decision,time,text}/ — each one carries an intro, a grid of every tool in the group, cross-links to other categories, and CollectionPage JSON-LD that Google parses into ItemList sitelinks.

Breadcrumbs across every tool page now resolve to a real three-level chain (Plinkr → Random tools → Coin Flip), replacing a placeholder structure that pointed at a non-existent querystring URL.

On the AI-assistant side: /llms-full.txt now ships the full text of every tool, published use case, and FAQ in one Markdown file per the llmstxt.org convention. ChatGPT, Claude, and Perplexity can now ingest the entire site in one request without scraping individual pages. The publication gate that hides scaffold use cases on the live site extends here too.

PWA: Plinkr is now installable on iOS and Android. Theme colors match the page background so the address bar blends with content instead of producing a hard color break. Apple touch icon and full icon set generated from the brand SVG.

Organization JSON-LD on the homepage names Plinkr as a brand entity for Google's entity graph (E-E-A-T). Profiles in sameAs will get added when launched. /.well-known/security.txt published per RFC 9116.