feat: capture worker artifacts before teardown and carry native limits

Assistant: codex
Assistant-Model: gpt-5.6-luna
Assistant-Session: 01a07ff8-19d0-7820-b4d0-1353833cb7fc

tests/test_gateway.py

@@ -553,3 +553,47 @@ def test_reachability_preparation_failure_is_reported_and_destroyed():
     assert 'private owner detail' not in str(post.call_args)
     assert rein.calls == []
     manager.destroy.assert_called_once_with('sbx1')
+
+
+def test_artifact_capture_occurs_after_cleanup_before_destroy():
+    manager = MagicMock()
+    manager.create.return_value = _fake_status()
+    rein = _FakeRein()
+    order = []
+    rein.cleanup_session = lambda session: order.append("cleanup")
+    manager.destroy.side_effect = lambda sandbox: order.append("destroy")
+    def capture(sandbox, summary):
+        assert summary.commit_sha == "deadbeef"
+        assert sandbox._owner_execute is not None
+        order.append("capture")
+    result = run_execution(_request(), catalog=_catalog_with_readiness(), rein=rein,
+        manager=manager, artifact_capture=capture)
+    assert result.ok
+    assert order == ["cleanup", "capture", "destroy"]
+    assert "bundle" not in result.model_dump_json()
+
+
+def test_artifact_capture_failure_still_destroys_sandbox():
+    manager = MagicMock()
+    manager.create.return_value = _fake_status()
+    def capture(*args):
+        raise ValueError("invalid artifact")
+    result = run_execution(_request(), catalog=_catalog_with_readiness(), rein=_FakeRein(),
+        manager=manager, artifact_capture=capture)
+    assert not result.ok
+    assert result.evidence.failure_stage == "artifact_capture"
+    assert result.evidence.sandbox_destroy == "succeeded"
+    manager.destroy.assert_called_once_with("sbx1")
+
+
+def test_cleanup_failure_never_captures_artifact():
+    manager = MagicMock()
+    manager.create.return_value = _fake_status()
+    rein = _FakeRein()
+    rein.cleanup_session = MagicMock(side_effect=ValueError("cleanup"))
+    capture = MagicMock()
+    result = run_execution(_request(), catalog=_catalog_with_readiness(), rein=rein,
+        manager=manager, artifact_capture=capture)
+    assert not result.ok
+    capture.assert_not_called()
+    manager.destroy.assert_called_once()