Updates language around AI Chat buttons in Security (#4533)

Partly addresses #4525 by updating the places in Elastic Security docs
where we mention "Open in AI Assistant" buttons. These will change to
"Add to chat" in spaces where Agent Builder is the active chat
experience.

This doesn't close the issue because it doesn't touch observability.

## Generative AI disclosure
1. Did you use a generative AI (GenAI) tool to assist in creating this
contribution?
- [ ] Yes  
- [ x] No

Author: benironside

solutions/security/ai/attack-discovery.md

@@ -90,7 +90,7 @@ You can select which alerts Attack Discovery will process by filtering based on
 :::{admonition} How to add non-ECS fields to Attack Discovery
 Attack Discovery is designed for use with alerts based on data that complies with ECS, and by default only analyses ECS-compliant fields. However, you can enable Attack Discovery to review additional fields by following these steps:
 
-1.  Select an alert with some of the non-ECS fields you want to analyze, and go to its details flyout. From here, use the **Ask AI Assistant** button to open AI Assistant.
+1.  Select an alert with some of the non-ECS fields you want to analyze, and go to its details flyout. From here, use the **Ask AI Assistant** or **Add to chat** button to open an AI chat.
 2.  At the bottom of the chat window, the alert's information appears. Click **Edit** to open the anonymization window to this alert's fields.
 3.  Search for and select the non-ECS fields you want Attack Discovery to analyze. Set them to **Allowed**.
 4.  Check the `Update presets` box to add the allowed fields to the space's default anonymization settings.
@@ -149,7 +149,7 @@ There are several ways you can incorporate discoveries into your {{elastic-sec}}
 * Hover over an entity’s name to either add the entity to Timeline (![Add to timeline icon](/solutions/images/security-icon-add-to-timeline.png "title =20x20")) or copy its field name and value to the clipboard (![Copy to clipboard icon](/solutions/images/security-icon-copy.png "title =20x20")).
 * Click **Take action**, then select **Add to new case** or **Add to existing case** to add a discovery to a [case](/solutions/security/investigate/cases.md). This makes it easy to share the information with your team and other stakeholders.
 * Click **Investigate in timeline** to explore the discovery in [Timeline](/solutions/security/investigate/timeline.md).
-* Click **View in AI Assistant** to attach the discovery to a conversation with AI Assistant. You can then ask follow-up questions about the discovery or associated alerts.
+* Click **View in AI Assistant** or **Add to chat** to attach the discovery to a conversation. You can then ask follow-up questions about the discovery or associated alerts.
 
 :::{image} /solutions/images/security-add-discovery-to-assistant.gif
 :alt: Attack Discovery view in AI Assistant

solutions/security/ai/ease/ease-alerts.md

@@ -31,6 +31,6 @@ You can take several actions from the alert details flyout:
    The recommended actions are informed by any relevant custom knowledge you may have added to the AI Assistant's [knowledge base](/solutions/security/ai/ai-assistant-knowledge-base.md). For example, if you have specified a particular teammate is responsible for a particular type of alert of part of your infrastructure, it would recommend contacting that person. 
    :::
 
-- **Ask AI Assistant**: To start a conversation with [AI Assistant](/solutions/security/ai/ai-assistant.md), select one of the suggested prompts or click **Ask AI Assistant**. 
+- **Ask AI Assistant** or **Add to chat**: To start an AI chat, select one of the suggested prompts or click **Ask AI Assistant** or **Add to chat**. 
 - **Add to case**: To add an alert to a new or existing case, scroll to the bottom and click **Take action**, then **Add to existing case** or **Add to new case**. 
 - **Apply alert tags**: To add tags to an alert, scroll to the bottom of its flyout and click **Take action**, then **Apply alert tags**. (To create new tags, navigate to the **Advanced settings** page using the navigation menu or the [global search field](/explore-analyze/find-and-organize/find-apps-and-objects.md), and update the **Alert tagging options**.)

solutions/security/ai/identify-investigate-document-threats.md

@@ -43,7 +43,7 @@ After Attack discovery outlines your threat landscape, use Elastic AI Assistant
 
 ## Use AI Assistant to analyze a threat [use-case-incident-reporting-use-ai-assistant-to-analyze-a-threat]
 
-From a discovery on the Attack discovery page, click **View in AI Assistant** to start a chat that includes the discovery as context.
+From a discovery on the Attack discovery page, click **View in AI Assistant** or **Add to chat** to start a chat that includes the discovery as context.
 
 :::{image} /solutions/images/security-attck-disc-remediate-threat.gif
 :alt: A dialogue with AI Assistant that has the attack discovery as context