Fixes for two defects found on 2.5.0 in production.
- A signed-in visitor who had not yet accepted the terms could not read
them: /terms is served by home#licence, which the acceptance gate did
not exempt, so the link the acceptance form itself offers bounced back
to the form.
- The source-licence migrator matched foreign sources by exact slug. WFO
is stored as WFO, the mapping key was wfo, so the largest taxonomic
source shipped without its licence while GBIF, POWO and USDA were
seeded. Matching is now case-insensitive, and a run reports the slugs
that found no row instead of passing over them.
- TAXONOMY.md records which source arbitrates names (WCVP), the ICN
nomenclature we store, and why an autonym is not interchangeable with
its species.
No migrations. Re-run Migrators::SourceLicencesWorker after deploying to
seed the WFO licence.