Point coding agents at the standards

Consult the standards shows how to set up AGENTS.md so coding agents read these standards before they act on anything the standards cover.

• A copy-pasteable AGENTS.md section points agents at /llms.txt as the source of truth and lists the work that needs a read first.
• CLAUDE.md stays a single import of AGENTS.md.
• The site sits behind Cloudflare Access, so engineers run cloudflared access login once, and the snippet tells an agent how to recover from a 302 redirect.
• The engineer-standards skill in NT-NinjaTrader/skills adds /standards-ask and /standards-check.