what are the responsibility of airbyte-cron service which runs in a saparate container. what it actually does ? why does it require credentials to connect to airbyte database ?

Hmm, I don't know enough to give you a confident answer yet. The provided extracts do not contain specific information about an "airbyte-cron" service. However, Airbyte does have a Scheduler component that is responsible for taking work requests from the API and sending them to the Temporal service to parallelize. It also tracks success/failure and triggers syncs based on the configured frequency. As for the credentials to connect to the Airbyte database, they are typically required for any service that needs to interact with the database. This is a common security measure to ensure that only authorized services can access and modify the data. For more detailed information, you may want to refer to the [Airbyte documentation](https://docs.airbyte.com/).