[Website]: Agent Builder isn't listed on that page

### Before you submit

- [x] This issue is about a documentation page, flow, or piece of content.

### Type of issue

Missing information

### What documentation page or section is affected

https://www.elastic.co/docs/solutions/security/security-serverless-feature-tiers

### What happened?

This info is missing from this page, we should figure out which tiers offer Agent Builder, and generally look for the various places in Security docs where we mention the AI Assistant to make sure we're also talking about Agent Builder/AI agent where needed

### Additional info

_No response_

> Generated by [Gh Aw Issue Triage](https://github.com/elastic/docs-content/actions/runs/28203007725) for issue #7110 · 21.3 AIC · ⌖ 9.75 AIC · ⊞ 9.1K · [◷](https://github.com/search?q=repo%3Aelastic%2Fdocs-content+is%3Aissue+%22gh-aw-workflow-call-id%3A+elastic%2Fdocs-content%2Fgh-aw-issue-triage%22&type=issues)

Start with the Security serverless feature tiers page linked in the issue, then search the Security docs for mentions of AI Assistant. Determine which tiers offer Agent Builder and identify the places where Agent Builder or AI agent coverage should accompany existing AI Assistant information; done when those updates are documented consistently.

Written by the indexing model from the issue text.