def _kill_process_using_port(self) -> bool:
        """Find and kill processes using the specified port."""
        killed = False
        
        for proc in psutil.process_iter(['pid', 'name']):
            try:
                process = psutil.Process(proc.info['pid'])
                for conn in process.net_connections():
                    if hasattr(conn, 'laddr') and len(conn.laddr) >= 2 and conn.laddr[1] == self.port:
                        try:
                            # Kill process more aggressively
                            process.kill()
                            process.wait(timeout=0.5)  # Reduced timeout
                            killed = True
                        except Exception:
                            # Last resort: try system kill
                            try:
                                os.kill(process.pid, signal.SIGKILL)
                                killed = True
                            except Exception:
                                pass
            except Exception:
                continue
                
        return killed
Find and kill processes using the specified port.
src/upsonic/server_manager.py