chore(run-ops split): add server-changes entry for ClickHouse replication fan-in

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: d-cs

.server-changes/run-ops-replication-fan-in.md

@@ -0,0 +1,6 @@
+---
+area: webapp
+type: feature
+---
+
+Replicate task runs into ClickHouse from multiple source databases so the run-ops DB split can fan both databases into analytics, with an admin status endpoint reporting per-source replication leadership.