UnsupportedByTarget
source: entity_model: entities.payment.fields.amount_usd
column 'amount_usd' of entity 'payment' applies the convert transform, but no rate relation is declared: a currency conversion is a join against a dated rate table, and the catalog carries no 'fx_rates:' (S-0040/phase-2-currency-as-a-declared-relation). Emitted as-is the model would compile here and fail on its first run. Fix: declare fx_rates: in the catalog with the relation and its from/to/rate/valid_from/valid_to columns, or drop the convert step and keep the amounts in their source currency
