Add third-party content disclaimer to AI Catalog

Note

This issue was created with GitLab Duo Agent.

Overview

We need to add a third-party content disclaimer to the AI Catalog page, similar to what currently exists on the CI/CD Catalog.

Requested Implementation

Add the following disclaimer text to the AI Catalog page:

This catalog contains third-party content. Use of this content is subject to the relevant content provider's terms of use. GitLab does not control and has no liability for third-party content.

Reference

• Positioning: The disclaimer should be positioned similarly to how it appears on the CI/CD Catalog: https://gitlab.com/explore/catalog
• Source discussion: https://gitlab.com/gitlab-com/legal-and-compliance/-/issues/2748#note_2933999909