With the introduction of MultiDB support ( PR) the same migration can run on multiple DBs.
As it stands right now, we have a different view per (Migration, db).
It would be valuable to have a holistic view of a Migration against all its possible DB targets in one place.
The migration detail view should collate the state of the Migration across all allowed_db_aliases.
If a migration file with an invalid migration id is added to the migration folder, we should add a warning to highlight that with a clear indication of what a valid ID looks like.
As it stands, the migration would not transparently appear in the list without a clear reason why.