- init() only the importer or exporter as required
- assign a "default user" user Id to credentials at creation if no user has been set
- "bridge auth": also display the user
- "bridge auth show": adapt to a potential "default user" user Id
- "bridge configure": allow to run without a user set
- "bridge pull": allow to run without a user set
- "user adopt": replace "default user" by the actual user id when run