- BrentPriceFetcher owns ingestion (fetchFromEia / fetchFromFred, each throws on failure)
- BrentPricePredictor owns prediction and marks latest brent_prices row as generated
- oil:fetch command tries EIA, falls back to FRED, fails loudly if both fail
- oil:predict command prompts if latest price already has a prediction; --force bypasses
- add prediction_generated_at column to brent_prices
- delete OilPriceService (replaced by the two focused services)
OilPriceService no longer inlines per-provider fetch/transform/error logic.
EIA and FRED are now their own classes with a common shape; the service
just iterates and upserts the first successful result.
