Update I Am Alive diagnostics and recovery details (#50087)

Updated the default timestamp update interval for diagnostics from 5 minutes to 30 seconds and added default value for missed timestamp limit.

Author: rkargMsft

docs/orleans/implementation/cluster-management.md

@@ -111,9 +111,9 @@ In addition to `IMembershipTable`, each silo participates in a fully distributed
 
     In addition to heartbeats sent between silos, each silo periodically updates an "I Am Alive" timestamp in its table row. This serves two purposes:
 
-    1. **Diagnostics**: Provides system administrators a simple way to check cluster liveness and determine when a silo was last active. The timestamp is typically updated every 5 minutes.
+    1. **Diagnostics**: Provides system administrators a simple way to check cluster liveness and determine when a silo was last active. The timestamp is by default updated every 30 seconds.
 
-    1. **Disaster recovery**: If a silo hasn't updated its timestamp for several periods (configured via `NumMissedTableIAmAliveLimit`), new silos ignore it during startup connectivity checks. This allows the cluster to recover from scenarios where silos crashed without proper cleanup.
+    1. **Disaster recovery**: If a silo hasn't updated its timestamp for several periods (configured via `NumMissedTableIAmAliveLimit`, default: 3), new silos ignore it during startup connectivity checks. This allows the cluster to recover from scenarios where silos crashed without proper cleanup.
 
 ### Membership table