Automatic resubmit: Show changed metadata fields

[max-moser]

It would be cool to see the "reason" for why a record was resubmitted for review after the request has been accepted.
Since the reason would typically be metadata edits, it would simplify the workflow for reviewers if a metadata diff could be displayed somewhere.

Perhaps we could calculate a diff in the service component and pass it as comment payload to the automatic resubmit action?
Or maybe it could be stored in the request's payload.

[max-moser]

i've done something simliar in our custom config package – sending notifications about the changed metadata fields when somebody else publishes edits.
the code & logic there is a bit wild, but maybe it can serve as a sort of inspiration.

the service component: https://gitlab.tuwien.ac.at/crdm/invenio-config-tuw/-/blob/v2025.1.12/invenio_config_tuw/services.py?ref_type=tags#L103-171
the task: https://gitlab.tuwien.ac.at/crdm/invenio-config-tuw/-/blob/v2025.1.12/invenio_config_tuw/tasks.py?ref_type=tags#L71-127

---

also note that in v13, the admin panel will have a feature that shows the metadata diffs between record revisions.
though i think that goes via the new revisions API endpoint and renders the diff in JS, so that's a little bit different.
(note that drafts don't have stored revisions, as opposed to published records)