## What
Add Serbian Dinar (RSD) as a supported currency.
## Compatibility
Conversion provider `@fawazahmed0/currency-api` covers RSD (standard ISO
4217). Conversion service lowercases codes and fetches `rsd.min.json` -
same path NZD uses. `exchange_rates` table stores rates as JSON, so any
3-letter code works. Validation rules and Inertia currency props
auto-derive from config via `CurrencyOptions`.
## Changes
- `config/currencies.php` - RSD entry (`allows_primary` +
`allows_account`)
- `lang/es.json` - Spanish translation
- `lang/fr.json` - French translation
## Tests
Haven't tested them locally, but should pass
934e16c0fa