fix polygon price

Author: kevinfaveri

packages/backend/src/services/price-cache.ts

@@ -20,7 +20,7 @@ const USDC_MINT = 'EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v';
 // CoinGecko IDs for EVM tokens
 const COINGECKO_IDS = {
   ETH: 'ethereum',
-  POL: 'matic-network',  // POL uses 'polygon' on CoinGecko
+  POL: 'polygon-ecosystem-token',  // POL uses 'polygon' on CoinGecko
   ARB: 'arbitrum',
   AVAX: 'avalanche-2',
 } as const;