Returns the list of countries where active RAID dive centers are present. Useful for populating a country filter dropdown before performing a dive center search. Results are sorted alphabetically by country name.
{"AU":"Australia","HR":"Croatia","EG":"Egypt","FR":"France","DE":"Germany","GR":"Greece","IT":"Italy","MT":"Malta","MX":"Mexico","ES":"Spain","TH":"Thailand","AE":"United Arab Emirates","US":"United States"}
This endpoint is called beforePOST /api/v1/dive_center to populate a country dropdown, so the user can filter dive centers by country without needing to know ISO codes.
1. GET /api/v1/dive_center/country → populate "Select country" dropdown
2. POST /api/v1/dive_center → { "country": "IT" } filters dive centers in Italy