Agent rule
Serve one landing page for apex and www; only the footer may differ by hostname — never maintain a second homepage.
Status: Accepted (revised — see ADR-018)
Context: We wanted a small personality moment on www, not a parallel site. AI agents default to duplicating pages when they see two hostnames.
Decision: Serve landing/index.html for www.differentthandefault.com — same page as apex, with a www-only footer note about subdomains.
Consequences: Deleted www/index.html. Agent updates one file; vercel.json rewrites www → /landing/index.html. Rule lives in project-conventions.mdc.