price-data

Add a new cryptocurrency with price data from CoinGecko to the Sablier price-data repo. Creates the coin config entry in src/config/coins.ts, creates crypto/<SYMBOL>_USD.tsv, and fetches historical USD prices via just fetch-crypto. Use when onboarding or adding a new crypto token, coin, or currency to this repo. Trigger phrases include add crypto, add coin, add currency, new token, onboard a coin.