Add llms.txt and llms-full.txt for public-facing sites

[RickCogley]

Context

Cloudflare's Markdown for Agents feature has been enabled on the esolia.co.jp domain zone:
https://blog.cloudflare.com/markdown-for-agents/

This means all sites under *.esolia.co.jp now support content negotiation — sending Accept: text/markdown returns clean Markdown instead of HTML.

Task

Add llms.txt and llms-full.txt to each public-facing site's static directory. These files should:

1. Describe the site's purpose and key sections
2. Include the following note about Markdown support:

All pages on this site support Markdown via content negotiation. To get any page as clean Markdown instead of HTML, send the request with the header Accept: text/markdown. The response will include an x-markdown-tokens header with an estimated token count.

3. Follow the llms.txt specification

Affected sites

Site	Domain	Status
Codex Portal	codex.esolia.co.jp	Needs llms.txt
Help	help.esolia.pro	Needs llms.txt (different zone — verify Markdown for Agents is enabled)
Demos	demos.esolia.co.jp	Needs llms.txt (site not yet deployed)
Hanawa CMS	hanawa.esolia.co.jp	Behind CF Access — add when public pages exist

Prerequisite

Public-facing site deployments need to be set up first. Hanawa CMS is currently the only deployed SvelteKit app, and it's behind Cloudflare Access.

References

• Cloudflare blog: https://blog.cloudflare.com/markdown-for-agents/
• llms.txt spec: https://llmstxt.org/
• Backpressure items 7-9 completed in the same session