For debugging purposes it would be very useful if both the server and the worker could expose their versions somewhere: specifically, the package version if running from a package, and otherwise the git commit ID. In the server case, it's relatively easy: it could render its version as part of the footer in its web views and/or in an HTTP header. In the worker case, the worker should report its version when it connects to the server, and the server should store this in the `Worker` table (it could be a separate column, or we could just stuff it into `dynamic_metadata`). `debusine-admin list_workers` should report this. When debugging task failures, it's often useful to know the worker version that was responsible for a particular task execution. Work requests already store a foreign key to the worker, and this is used to show the worker name in the generic work request detail view; however, I think we should also store a copy of the worker's version in `WorkRequest` so that we can show that too.