llms optimisations

[thisisjofrank]

• Added LLM resource outputs: llms-summary.txt and structured llms.json (from Orama summary), plus generation wiring in build and test scripts.
• Improved LLM generation to parse YAML frontmatter, respect frontmatter URLs, and add summaries when descriptions are missing.
• Added AI entrypoint page and linked it from llms.txt
• updated robots.txt to allow LLM-related endpoints.
• Fixed malformed frontmatter title
• Linked John's Deno LLM Skills repo in the Optional section of LLM indexes.