refactor: improve server initialization and port handling

- Separate server setup from initialization\n- Add port availability check utility\n- Fix double server start issue\n- Improve error handling for port conflicts

src/utils/portCheck.ts

@@ -0,0 +1,18 @@
+import net from 'net';
+
+export function isPortAvailable(port: number | string): Promise<boolean> {
+  return new Promise((resolve) => {
+    const server = net.createServer();
+
+    server.once('error', () => {
+      resolve(false);
+    });
+
+    server.once('listening', () => {
+      server.close();
+      resolve(true);
+    });
+
+    server.listen(port);
+  });
+}