A resource-cache migration (0013_resource_cache.sql) was merged onto main concurrently and also claimed version 0013. LoadMigrations rejects any duplicate migration version, so the app would refuse to boot with both files present.
Renumber the discoverable-login migration to 0014. The two migrations touch disjoint objects (0013 ALTERs servers to add cached_* columns; this one CREATEs webauthn_discoverable_challenges), so their relative order does not matter, and the table name is unchanged -- no Go reference moves.
Renaming a just-published migration is safe here because neither version has been applied to a persistent database yet: there is no schema_migrations row for version 13 to reconcile. This is a pre-application renumber, not a history rewrite of an already-applied migration.