Questione giuridica chiave
Whether the public-law appeal was admissible on the merits against the refusal to renew the residence permit.
Decisione estratta
No admissible merits review was available because the applicants had no entitlement to a residence permit under federal law or a treaty.
Motivazione estratta
Without a right to the permit, ordinary administrative appeal was excluded and public-law appeal could not be used to contest the merits.