[DOCS][ML UI][9.x & Serverless] Host Elastic documentation for AI assistant

[nastasha-solomon]

Summary

This PR fixes #5519 and continues work started in elastic/kibana#259418. More details are below in the section requesting reviews.

Generative AI disclosure

1. Did you use a generative AI (GenAI) tool to assist in creating this contribution?

• Yes
• No

Cursor + Composer 2

Reviews needed

This PR needs an editorial, technical, and code owner review. Instructions for each are below.

📋 What this PR does

This PR adds Host a knowledge base artifact repo for AI assistants (a new page) to the AI chat experiences section. It ports and reorganizes procedural content that previously lived in the Kibana AI Assistant settings reference, and adds net-new content (generated with AI assistance) covering three hosting options for air-gapped or restricted network deployments: S3-compatible bucket, CDN, and local file path.

Several other files have minor updates to replace or add cross-references pointing to the new page.

📁 Files changed

File	Change
explore-analyze/ai-features/ai-chat-experiences/ai-assistant-host-doc-artifacts.md	New file — primary content (266 lines)
explore-analyze/toc.yml	New TOC entry for the page above
deploy-manage/deploy/self-managed/air-gapped-install.md	applies_to tag changed from stack to self; updated cross-reference
explore-analyze/ai-features/llm-guides/connect-to-lmstudio-observability.md	Updated cross-reference
solutions/observability/ai/observability-ai-assistant.md	Updated cross-reference
solutions/security/ai/ai-assistant-knowledge-base.md	Updated cross-reference

✏️ Editorial reviewer

Please review the new page and the updated cross-references for:

• Clarity and flow: Does the intro clearly explain the problem being solved? Is the "Choose a hosting option" section easy to scan?
• Consistency: Do the three tab sections (S3, CDN, local files) follow a parallel structure? Are steps labeled and ordered consistently across tabs?
• Style guide compliance: There's an open Vale warning flagging via on line 10 of the new file — please confirm the fix. Check for any other style issues (tone, active voice, second person, etc.).
• Cross-references: Do the updated link labels in the existing files read naturally in context?
• Frontmatter: Does the page description accurately reflect the content?

🔧 Technical reviewer

Please review the new page for technical accuracy. The net-new content especially needs validation. Focus on:

• ZIP file names and versioning: Are the file name patterns (kb-product-doc-{product}-{major}.{minor}.zip) accurate? Are the example filenames for 9.0 correct and complete? (Note: The tech reviewer has flagged that in 9.4, a new kb-product-doc-openapi-9.4.zip will be added. This will be doc'd in a separate PR once the implementation PR adding that zip file is merged.)
• S3-compatible bucket instructions: Is the guidance about bucket listing behavior (S3-style ListObjects response, object key requirements) accurate? Are there missing edge cases or gotchas?
• CDN instructions: Is the bucket listing XML template correct? Are the instructions for serving it as a directory index accurate across common CDN setups?
• Local file path instructions: Is the file:// URI approach described correctly? Are the permissions guidance and constraints accurate?
• xpack.productDocBase.artifactRepositoryUrl: Are the configuration examples and constraints correct?

Related Kibana PR for context: elastic/kibana#259418

👤 Code owner reviewers

Please review only the files listed for you below and confirm that the changes to your area are correct, don't introduce inaccuracies, and don't conflict with anything in progress or recently merged.

@[CODEOWNER_HANDLE] please review:

• solutions/observability/ai/observability-ai-assistant.md: [DESCRIBE THE SPECIFIC CHANGE]

@[CODEOWNER_HANDLE] please review:

• deploy-manage/deploy/self-managed/air-gapped-install.md: [DESCRIBE THE SPECIFIC CHANGE]

• Is the change technically correct?

• Does it accurately represent the behavior/feature in your area?

• Does it conflict with anything in progress or recently merged?

• Are there missing details or anything that could mislead users?

[qn895]

Just a heads up, in 9.4, we are adding a new zip file called kb-product-doc-openapi-9.4.zip which will be installed at the same time as these 4 files. The zip file will support elastic/kibana#255717, which dynamically generates elasticsearch tools for the agent builder. So customer should also install that for 9.4+ version after the PR is merged.

[github-actions]

🔍 Preview links for changed docs

• deploy-manage/deploy/self-managed/air-gapped-install.md
• explore-analyze/ai-features/ai-chat-experiences/ai-assistant-host-doc-artifacts.md
• explore-analyze/ai-features/llm-guides/connect-to-lmstudio-observability.md
• solutions/observability/ai/observability-ai-assistant.md
• solutions/security/ai/ai-assistant-knowledge-base.md

[github-actions]

✅ Vale Linting Results

No issues found on modified lines!

---

The Vale linter checks documentation changes against the Elastic Docs style guide.

To use Vale locally or report issues, refer to Elastic style guide for Vale.

[yetanothertw]

The Admin docs-related changes look good, thanks!

Approving to unblock, but left a suggestion to simplify that last paragraph.

[florent-leborgne]

Really nice, leaving a suggestion regarding the "titles inside of tabs" issue that I think we should fix

[nastasha-solomon]

Thanks for the early feedback @yetanothertw and @florent-leborgne . I'm actually still working on this PR, which is why I reverted it back to draft mode.