[Docs] Guide agents through Roomote self-hosting

[roomote-roomote]

Created by Roomote. Follow up by mentioning @roomote-roomote, in the web UI, or in Slack.

What changed

Added site-wide Markdown instructions that guide agents through self-hosted Roomote setup while preserving Mintlify's automatically generated llms.txt documentation index.

The guidance distinguishes operator deployments from contributor development, defaults fresh servers to the one-command installer, establishes infrastructure and secret-handling guardrails, requires end-to-end verification, and defines the operational handoff a self-hoster should receive.

Why this change was made

The generated llms.txt exposed the documentation structure but gave agents no opinionated setup workflow. Agents can now discover the correct deployment path and completion criteria without Roomote maintaining a separate static index.

Impact

Mintlify includes these instructions in llms.txt, llms-full.txt, and Markdown page exports. Human-facing documentation and the generated page index remain unchanged.

[roomote-community]

No code issues found. See task

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