Fix: Bind backend to 0.0.0.0 in Docker to fix healthcheck failures and frontend proxy connection refused errors

backend/server.js

@@ -152,12 +152,11 @@ app.use((err, req, res, next) => {
 });
 
 // ─── Start Server ─────────────────────────────────────────────────────────────
-// Bind to 127.0.0.1 in production to prevent direct external access to port 3001.
-// All external traffic must go through the reverse proxy (Apache/Nginx) at port 80/443.
-const BIND_HOST = process.env.NODE_ENV === 'production' ? '127.0.0.1' : '0.0.0.0';
+// Use BIND_HOST from environment or default to 0.0.0.0 for Docker compatibility
+const BIND_HOST = process.env.BIND_HOST || '0.0.0.0';
 app.listen(PORT, BIND_HOST, () => {
   console.log(`\n🚀 BackOne API Server berjalan di http://${BIND_HOST}:${PORT}`);
   console.log(`🔌 API Health : http://${BIND_HOST}:${PORT}/api/health`);
   console.log(`📡 Mode       : READ-ONLY dari MongoDB (data dikirim oleh Proxy Server)`);
-  console.log(`🔒 Security   : Bound to ${BIND_HOST} (internal only in production)\n`);
+  console.log(`🔒 Security   : Bound to ${BIND_HOST}\n`);
 });