Add PostgreSQL support
I don't know if sncf will easily be subject to database locks (I suspect updating the timestamp of an account
Form.updated_at might cause some load somehow).
Even though it should be fine for some time, SQLite is still bad for a web application. I've used it because it was the easiest way to start the project, but Postgres is waaaay batter.
Fixed by commit
Note: No database overload / lock has been detected after 2 months in production, so SQLite should be safe enough. But it might be better to use the same database system as Nextcloud's to centralize all data.
Deleting a branch is permanent. It CANNOT be undone. Continue?