Option to Pin or Permanently Close Onboarding on Client Dashboard

Add a setting that allows agencies or clients to either pin the onboarding section to remain visible on the client dashboard or permanently close it once onboarding is complete.

Some agencies use this area to host key resources like videos and links that should stay accessible, while others use it only for the initial onboarding process. Giving clients the ability to hide it when no longer needed improves usability and reduces dashboard clutter.