Immutable datastore library?

I would like to use Postgres as an immutable data store. A subject table would have a timestamp column, and that would be added to what would otherwise be the primary key.

Trap updates and turn them into inserts. Have an associated _deleted table. Trap deletes and turn them into inserts of the primary key into that table.

Create a view that only shows the non-deleted records with the most recent timestamps.

Stored procedure to do all that to a table. Event trigger to drop and re-create the view on changes to the table columns.

I think that's about it. Seems an obvious and nice general-purpose thing to do. It also seems like something someone might have already done, but googling "immutable postgres" pulls up things about writing functions.

Does anyone know of a project that has already done this?