Make docs site LLM-friendly

[KMajkrzakOctopus]

The problem: when AI tools like ChatGPT or Claude try to read our docs to answer customer questions, they often fail. Our docs pages were so heavy with navigation menus and chrome that the AI ran out of room before reaching the actual content.

What this branch ships:

1. Slimmed down the HTML itself by removing duplicated navigation that no human ever saw but bloated every page for AI crawlers.
2. A "lite" version of every docs page, tailored for AI tools. Same content, none of the chrome. Smaller per page, so AI tools can fit the whole article in one fetch instead of getting cut off.
3. An index file that lists every page, so any AI tool that knows the standard convention auto-discovers our entire docs library in one request.
4. A "llms-full" file with every page concatenated together, for use cases like "feed our complete docs into an AI assistant".
5. A small dropdown on every docs page saying "Use Octopus docs with AI" - allows to copy the page as plain text or open the AI-friendly version with one click.

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