FIX Handle Ctrl+C cancellation in CLI scenario polling (#3747) (#3813)

Co-authored-by: Roman Lutz <romanlutz13@gmail.com>

Author: Rohitpro1

pyrit/cli/pyrit_scan.py

@@ -1112,11 +1112,12 @@ async def _run_scenario_async(
             client=client,
             scenario_result_id=scenario_result_id,
         )
-    except KeyboardInterrupt:
+    except (KeyboardInterrupt, asyncio.CancelledError):
         print("\n\nCancelling scenario run...")
+        cancellation_task = asyncio.create_task(client.cancel_scenario_run_async(scenario_result_id=scenario_result_id))
         try:
-            await client.cancel_scenario_run_async(scenario_result_id=scenario_result_id)
-            print("Scenario run cancelled.")
+            await asyncio.shield(cancellation_task)
+            print("Cancellation request sent to server.")
         except Exception:
             print("Warning: could not cancel scenario run on server.")
         return 1

tests/unit/cli/test_pyrit_scan.py

@@ -5,6 +5,7 @@
 Unit tests for the pyrit_scan CLI module (thin REST client).
 """
 
+import asyncio
 import logging
 from argparse import Namespace
 from datetime import UTC
@@ -89,6 +90,20 @@ def test_compatibility_failure_exits_without_replay(stage, capsys):
         assert "server run may still be active" in output
 
 
+def test_run_scenario_cancellation_requests_server_cancellation(capsys):
+    client = _mock_api_client()
+    with (
+        patch("pyrit.cli.api_client.PyRITApiClient", return_value=client),
+        patch("pyrit.cli._server_launcher.ServerLauncher.probe_health_async", new=AsyncMock(return_value=True)),
+        patch.object(pyrit_scan, "_poll_until_terminal_async", new=AsyncMock(side_effect=asyncio.CancelledError)),
+    ):
+        exit_code = pyrit_scan.main(["run", "test_scenario", "--target", "t"])
+
+    assert exit_code == 1
+    client.cancel_scenario_run_async.assert_awaited_once_with(scenario_result_id="test-id-123")
+    assert "Cancellation request sent to server." in capsys.readouterr().out
+
+
 def test_dataset_filter_help_covers_every_request_model_key():
     """
     The frontend per-key ``--dataset-filters`` help must describe exactly the server-side allow-list.