Debug session becomes unsynchronized during long `step_over` and cannot be stopped

I’m seeing inconsistent behavior when DebugMCP handles long-running operations during step_over.

Scenario 1 – Function with sleep

demo_run.py

from utils import demo

def main() -> None:
    print('Start')
    demo()
    print('End')

if __name__ == "__main__":
    main()

utils.py

from time import sleep

def demo():
    sleep(100)
    print('in demo')

Failure Behavior:

When execution reaches demo() and sleep(100) is still running, step_over fails with:
Debug session is not ready. Please wait for initialization to complete.
Attempting stop_debugging afterward fails with:
No active debug session to stop

In the end the debug session is still running and must be terminated manually.

Scenario 2 – Sleep inside main

from time import sleep

def main() -> None:
    print('Start')
    sleep(100)
    print('End')

if __name__ == "__main__":
    main()

Result: step_over times out while sleep(100) is still executing, and the agent later fails to stop debugging.

Issues:

1. step_over times out or reports invalid session while code is still executing.
2. stop_debugging fails to terminate an active session after such errors.

Expected Behavior:

• Long-running execution should not invalidate the session.
• step_over should wait or return a clear "execution in progress" state.
• stop_debugging should reliably stop any active session.

Reproduce the issue with the provided demo_run.py and utils.py scenarios, then trace the step_over and stop_debugging entry points through session state and timeout handling. Done means long-running sleep calls do not invalidate the session, step_over reports a clear in-progress state or waits, and stop_debugging terminates the active session.