Explorer shows the One Piece Promos block. French set fr-OP-PROMOS is still missing from GET /sets?lang=fr, and GET /sets/fr-OP-PROMOS?lang=fr returns 404. Its block_logo.id should be onepiece-promo.

Merged into app staging in #917 as dcf9291f1f239c867d0caf8771fafe7e947a8935. Not deployed. Local gates only.