Retention docs improved(#873)

Author: margaritagomez

fern/assistants/call-recording.mdx

@@ -520,7 +520,9 @@ Use artifact data for comprehensive insights:
   </Accordion>
 
   <Accordion title="How long are artifacts stored?">
-    Default retention is 30 days for all artifacts. You can configure custom retention policies and use custom storage for longer-term archival.
+    Retention periods vary by plan:
+    - **Pay-As-You-Go:** Up to 30 days for chats and 14 days for calls
+    - **Enterprise:** Configurable retention policies 
   </Accordion>
 
   <Accordion title="How do artifacts work with squad transfers?">