Load backend env file reliably

backend/src/config.js

@@ -1,6 +1,12 @@
 import dotenv from 'dotenv';
+import { dirname, resolve } from 'node:path';
+import { fileURLToPath } from 'node:url';
 
-dotenv.config();
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+const envPath = resolve(__dirname, '../.env');
+
+dotenv.config({ path: envPath });
 
 const bool = (value, fallback = false) => {
   if (value === undefined || value === null || value === '') return fallback;