Add data lifecycle links to quickstarts (#3130)

In a review of the ILM docs it was requested that we add links to those
docs from various quickstarts, etc.

Rel:
#1568

As part of that, this PR adds a link at the end of security SIEM and
endpoint security tutorials:
<img width="579" height="383" alt="lifecycle-sec1"
src="https://github.com/user-attachments/assets/dc7a2e49-0257-4cdc-8d88-f26e2e06a651"
/>

---

Please see previews:
- SIEM tutorial [next
steps](https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/3130/solutions/security/get-started/get-started-detect-with-siem#next-steps)
- endpoint security [next
steps](https://docs-v3-preview.elastic.dev/elastic/docs-content/pull/3130/solutions/security/get-started/get-started-endpoint-security#next-steps)

Author: kilfoyle

solutions/security/get-started/get-started-detect-with-siem.md

@@ -176,4 +176,5 @@ Once you've had a chance to install detection rules and check out alerts, we rec
 * Learn how to use [Cases](/solutions/security/investigate/cases.md) to track investigation details.  
 * Download the "Guide to high-volume data sources for SIEM" [white paper](https://www.elastic.co/campaigns/guide-to-high-volume-data-sources-for-siem?elektra=organic&storm=CLP&rogue=siem-gic). 
 * Check out [Elastic Security Labs](https://www.elastic.co/security-labs) for the latest on threat research.  
+* Learn how to manage your [data lifecycle](/manage-data/lifecycle.md), including how long data is retained, and how indices can be transitioned through data tiers according to your performance needs and retention policies.
 % add endpoint getting started guide when it's done 

solutions/security/get-started/get-started-endpoint-security.md

@@ -119,4 +119,5 @@ After your hosts are secure and your environment has all the appropriate securit
 
 * Check out the [Hosts page](/solutions/security/explore/hosts-page.md) for a comprehensive overview of all hosts and host-related security events. This page is also useful to identify uncommon processes and anomalies discovered by {{ml}} jobs. 
 *  Enable prebuilt detection rules. You're already set to receive endpoint threat alerts from {{elastic-defend}}, but did you know {{elastic-sec}} ships with several out-of-the-box rules that you can enable? Check out our [SIEM quick start guide](/solutions/security/get-started/get-started-detect-with-siem.md#add-elastic-prebuilt-detection-rules) or our [documentation](/solutions/security/detect-and-alert/install-manage-elastic-prebuilt-rules.md#load-prebuilt-rules).  
-* Discover all the other tools available to [manage {{elastic-defend}}](/solutions/security/manage-elastic-defend.md). 
+* Discover all the other tools available to [manage {{elastic-defend}}](/solutions/security/manage-elastic-defend.md). 
+* Learn how to manage your [data lifecycle](/manage-data/lifecycle.md), including how long data is retained, and how indices can be transitioned through data tiers according to your performance needs and retention policies.