Goal: make the OpenAPI spec findable by search engines and coding agents. PingArthur is LLM-first, so the spec IS the docs; getting an agent from the bare domain to the spec in one hop is the whole win. - homepage.go: canonical link, Twitter card tags, SoftwareApplication JSON-LD with creator pointing at raedisch.net and sameAs to the Bluesky profile + Tangled repo - seo.go (new): inline /robots.txt, /sitemap.xml, /llms.txt handlers. Same embedded-string pattern as homepageHTML — keeps the binary self-contained, no separate asset deploy needed - main.go: register the three new routes - openapi_test.go: exempt SEO routes from the route↔spec drift check (they're crawler surfaces, not API contract) - openapi.json: fix stale externalDocs URL — tangled.sh/@divepool.social/pingarthur (2 redirects) → tangled.org/divepool.social/pingarthur (canonical, 200 direct) - Caddyfile.j2: forward the three SEO paths to the Go binary Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>