Specify a local Docker repository

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Is your feature request related to a problem? Please describe.
I can only deploy the Agenta service within my local network and do not have access to the internet. Therefore, when deploying services or using command-line tools, errors occur due to the inability to access external image repositories. This limits my ability to update and manage Docker images and makes it difficult to deploy new service versions.

Describe the solution you'd like
I would like to be able to specify the image repository address when deploying services and using the agenta variant serve command. This way, I can point to a local Docker repository to pull images, ensuring that services can be deployed and run correctly even without an internet connection. Ideally, this setting could be specified through a configuration file or command-line parameters, making it easy to integrate into existing workflows.

Describe alternatives you've considered
As an alternative, I have tried manually downloading the required images to the local machine and importing these images using the docker load command. However, this method increases the complexity of deployment and requires repeating the process each time a new image is needed. Additionally, this approach is not conducive to collaboration among team members, as they must each maintain their own local copies of the images.

Additional context
Considering our development environment is often located in restricted network environments, this feature would be highly valuable to many users. It not only enhances flexibility but also strengthens security since we don't need to rely on external networks to obtain images. Supporting a local image repository would also better accommodate CI/CD pipelines, enabling automated build and deployment processes in isolated network environments.