test: manage runners at every scope, rerun and delete a completed run, fail when the runner is required

tests/integration/conftest.py

@@ -35,6 +35,25 @@ _HERE = Path(__file__).parent.resolve()
 ENABLE_ENV = "AEGIS_INTEGRATION"
 
 
+REQUIRE_RUNNER_ENV = "AEGIS_IT_REQUIRE_RUNNER"
+
+
+def runner_required() -> bool:
+    """True when a runner that cannot start must fail the test instead of xfailing it.
+
+    Set by the CI job (``AEGIS_IT_REQUIRE_RUNNER=1``) and implied by ``CI``: a pipeline that
+    silently skips the Actions scenario would hide a broken runner setup.
+    """
+    return os.environ.get(REQUIRE_RUNNER_ENV) == "1" or bool(os.environ.get("CI"))
+
+
+def runner_unavailable(reason: str) -> None:
+    """Report that the act_runner could not start or come online (fails or xfails)."""
+    if runner_required():
+        pytest.fail(f"act_runner unavailable: {reason}", pytrace=False)
+    pytest.xfail(reason)
+
+
 def integration_enabled() -> bool:
     """Return True when the opt-in env var is set."""
     return os.environ.get(ENABLE_ENV) == "1"