Provide a UI for updating workloads automatically

There are two types of potential backend implements. For the Argo CD image updater solution, we need to let users know it's not ready for the production environment.

No files, tests, or entry points are named. First clarify the two proposed backend implementations and the intended workload-update UI, then determine how the Argo CD image updater's production-readiness warning should be represented. Done means the scope, implementation choice, and production behavior are agreed and documented.

Written by the indexing model from the issue text.