[DOCS-14295] Add configuring Agent integrations to Fleet Automation docs (#37105)

* First draft of the procedure and background info

* Add Configure Agent Integrations to nav and clean up draft

* Tweak intro and Preview banner

* Apply suggestions from code review

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

* Finalize delete operation

* Remove blank line

* Omit unnecessary detail

* Add tip about configuration summary panel

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Author: evazorro

config/_default/menus/main.en.yaml

@@ -560,16 +560,21 @@ menu:
       url: agent/fleet_automation/configure_agents
       parent: agent_fleet_automation
       weight: 802
+    - name: Configure Agent Integrations
+      identifier: configure_integrations
+      url: agent/fleet_automation/configure_integrations
+      parent: agent_fleet_automation
+      weight: 803
     - name: Upgrade Agents
       identifier: upgrade_agents
       url: agent/fleet_automation/upgrade_agents
       parent: agent_fleet_automation
-      weight: 803
+      weight: 804
     - name: Upgrade SDKs
       identifier: upgrade_sdks
       url: agent/fleet_automation/upgrade_sdks
       parent: agent_fleet_automation
-      weight: 804
+      weight: 805
     - name: Troubleshooting
       url: agent/troubleshooting/
       parent: agent

content/en/agent/fleet_automation/configure_integrations.md

@@ -0,0 +1,82 @@
+---
+title: Configure Agent Integrations
+description: "Remotely configure Datadog Agent integrations at scale with Fleet Automation."
+further_reading:
+- link: "/agent/fleet_automation/"
+  tag: "Documentation"
+  text: "Fleet Automation"
+- link: "/agent/fleet_automation/configure_agents/"
+  tag: "Documentation"
+  text: "Configure Agents"
+- link: "/api/latest/fleet-automation/"
+  tag: "Documentation"
+  text: "Fleet Automation API"
+---
+
+{{< callout btn_hidden="true" header="Join the Preview!" >}}
+Remote integration configuration is in Preview.
+{{< /callout >}}
+
+Fleet Automation can deploy, update, and remove [integration][1] configuration files (`conf.d`) on your Agents remotely. Select target Agents by host or tag, choose an integration, and Fleet Automation pushes the configuration change across your fleet.
+
+## Prerequisites
+
+- [Remote Configuration][2] enabled for your organization
+- Agent version 7.76 or later
+- Linux VMs (installed with the install script or the Ansible Datadog Role) or Windows VMs
+
+<div class="alert alert-info">
+Configuring integrations on Agents in containerized workloads is not supported.
+</div>
+
+## Compatibility
+
+Fleet Automation supports configuring out-of-the-box integrations that have a `conf.d` configuration file, such as Redis, MySQL, and Windows Certificate Store.
+
+Custom checks are **not** supported.
+
+## Configure integrations across multiple Agents
+
+<div class="alert alert-tip">As you step through the configuration wizard, the <strong>Configuration Summary</strong> panel shows your current selected scope of Agents. Use this to check how a change would affect an Agent by previewing configuration diffs on a specific Agent in scope.</a></div>
+
+1. In Fleet Automation, open the [{{< ui >}}Configuration{{< /ui >}}][3] tab and click {{< ui >}}Configure Agents{{< /ui >}}.
+1. Scope the configuration to the target Agents. Filter by host information or tags to target a specific group.
+1. Choose {{< ui >}}Agent integrations{{< /ui >}}.
+1. Select the integration to configure.
+
+    <div class="alert alert-info">Fleet Automation can detect unconfigured integrations on your hosts. If a process is running on a host that has an available Datadog integration but no active configuration, it appears in the list of <strong>Unconfigured integrations detected on your hosts</strong>. Use this to identify monitoring gaps across your fleet.</div>
+
+1. Select an operation (see [How configuration changes are applied](#how-configuration-changes-are-applied) for more information about each operation):
+
+    - {{< ui >}}Add New{{< /ui >}}. Specify the filename for the new configuration file, and fill in the configuration as prompted.
+    - {{< ui >}}Edit & Replace{{< /ui >}}. Click {{< ui >}}Select a file{{< /ui >}} and choose the configuration file you want to replace, then fill in the new configuration as prompted.
+    - {{< ui >}}Delete{{< /ui >}}. Click {{< ui >}}Select a File to Delete{{< /ui >}}.
+
+    <div class="alert alert-tip">Toggle between <strong>Visual</strong> and <strong>YAML</strong> mode when filling out the integration configuration. Use <strong>YAML</strong> mode to paste in YAML directly.</div>
+
+1. Review the deployment plan. Fleet Automation generates a configuration diff for each affected Agent so you can verify the exact changes.
+1. Click {{< ui >}}Deploy Configuration{{< /ui >}} to start the deployment. Track progress from the [Deployments page][4].
+
+## How configuration changes are applied
+
+Each operation applies changes to the integration's `conf.d` configuration file differently:
+
+- {{< ui >}}Add New{{< /ui >}}: Deploys a new integration configuration file. If a configuration file already exists, it is replaced entirely and the YAML you provide becomes the complete new configuration for that integration on the target Agents.
+
+- {{< ui >}}Edit & Replace{{< /ui >}}: Only the fields you specify are modified; unmentioned fields remain unchanged.
+
+  <div class="alert alert-warning">
+  Array fields (such as <code>tags</code>) are fully replaced during an Edit & Replace, not merged. Include all desired values in your update. Any values you omit are removed.
+  </div>
+
+- {{< ui >}}Delete{{< /ui >}}: Removes the integration configuration file from the target Agents.
+
+## Further Reading
+
+{{< partial name="whats-next/whats-next.html" >}}
+
+[1]: /integrations/
+[2]: /agent/guide/setup_remote_config
+[3]: https://app.datadoghq.com/fleet/agent-management
+[4]: https://app.datadoghq.com/fleet/deployments
+[5]: https://www.rfc-editor.org/rfc/rfc7386