chore: document and standardize hosts/ports across apps

apps/Backend/src/index.ts

@@ -3,11 +3,18 @@ import dotenv from "dotenv";
 
 dotenv.config();
 
-const HOST = process.env.HOST;
-const PORT = process.env.PORT;
+const NODE_ENV = (
+  process.env.NODE_ENV ||
+  process.env.ENV ||
+  "development"
+).toLowerCase();
+const HOST = process.env.HOST || "0.0.0.0";
+const PORT = Number(process.env.PORT) || 5000;
 
-const server = app.listen(PORT, () => {
-  console.log(`✅ Server running at http://${HOST}:${PORT}`);
+const server = app.listen(PORT, HOST, () => {
+  console.log(
+    `✅ Server running in ${NODE_ENV} mode at http://${HOST}:${PORT}`
+  );
 });
 
 // Handle startup errors