fix(eiger): expose auto_reinitialize as a device attribute

The device server applies deviceConfig entries via update_config, which rejects keys
that are not attributes of the device ("Unknown config parameter"). A constructor
argument alone is therefore not enough to set auto_reinitialize from the config.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YAEkW1wjZszVKkhQrD8Ad5

csaxs_bec/devices/jungfraujoch/eiger.py

@@ -247,6 +247,18 @@ class Eiger(PSIDeviceBase):
                 return
             self.preview_image.put(frame)
 
+    # NOTE The device server applies every deviceConfig entry through update_config, which only
+    # accepts keys that exist as attributes of the device. Hence this needs to be a property,
+    # a constructor argument alone is rejected with 'Unknown config parameter'.
+    # pylint: disable=missing-function-docstring
+    @property
+    def auto_reinitialize(self) -> bool:
+        return self._auto_reinitialize
+
+    @auto_reinitialize.setter
+    def auto_reinitialize(self, value: bool) -> None:
+        self._auto_reinitialize = bool(value)
+
     # pylint: disable=missing-function-docstring
     @property
     def detector_distance(self) -> float:

tests/tests_devices/test_eiger.py

@@ -903,3 +903,12 @@ def test_jfj_client_wait_for_idle_reports_broker_message():
         with pytest.raises(JungfrauJochClientError, match="WrongDAQState"):
             client.wait_for_idle(timeout=1)
         assert client.wait_for_idle(timeout=1, raise_on_timeout=False) is False
+
+
+def test_eiger_auto_reinitialize_is_a_config_attribute(eiger_1_5m):
+    """The device server rejects deviceConfig keys that are not attributes of the device."""
+    eiger = eiger_1_5m
+    assert hasattr(eiger, "auto_reinitialize")
+    assert eiger.auto_reinitialize is False
+    eiger.auto_reinitialize = True
+    assert eiger._auto_reinitialize is True