Update dotenv configuration to specify environment file path

src/index.js

@@ -1,4 +1,6 @@
 import dotenv from 'dotenv';
+import path from 'path';
+import { fileURLToPath } from 'url';
 import express from 'express';
 import http from 'http';
 import cors from 'cors';
@@ -11,7 +13,8 @@ import walletRoutes from './routes/wallet.js';
 import pool from './db.js';
 import { setupWebSocket } from './ws.js';
 
-dotenv.config();
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+dotenv.config({ path: path.join(__dirname, '..', '.env') });
 
 const app = express();