fix: shutdown server on SIGTERM

packages/backend/src/server.ts

@@ -1,3 +1,4 @@
+import type { Server } from 'http';
 import app from './app';
 import appConfig from './config/app';
 import logger from './helpers/logger';
@@ -7,6 +8,14 @@ telemetry.setServiceType('main');
 
 const port = appConfig.port;
 
-app.listen(port, () => {
+const server: Server = app.listen(port, () => {
   logger.info(`Server is listening on ${port}`);
 });
+
+function shutdown(server: Server) {
+  server.close();
+}
+
+process.on('SIGTERM', () => {
+  shutdown(server);
+});