Notify Caller Upon Configuration Sync Completion

[ChaitanyaSingla]

Problem/Opportunity

Currently, once the CPE successfully syncs its configurations from WebConfig, there is no feedback mechanism for WebConfig to inform the caller (backend system) that the sync is complete.
This creates a visibility gap — the backend has no confirmation whether the CPE is fully up-to-date with the latest configurations.

Proposed Solution

Introduce a mechanism in WebConfig to notify the caller once the CPE has completed syncing its configurations.
This could be implemented via:

1. A callback endpoint provided by the caller, which WebConfig invokes upon successful sync.
2. A message/event published to a message queue or event bus that the caller can listen to.

cc: @Sachin4403