* Release 2.9.9

Carries #473 (species.hidden_reason, bryophytes and fossils hidden) and
#474 (Migrators::StaleFactProjection), which the 2026-10 data passes need
in the image the crawlers build on. One additive migration
(20261014150000_add_hidden_reason_to_species).

* OpenAPI spec: version 2.9.9