Start adding stage test and apply fixes to base class

src/openflexure_microscope_server/things/stage/__init__.py

@@ -88,18 +88,18 @@ class BaseStage(lt.Thing):
     axis_direction = lt.ThingSetting(
         initial_value={"x": 1, "y": 1, "z": 1},
         model=Mapping[str, int],
+        readonly=True,
     )
     """Used to convert coordinates between the program frame and the hardware frame."""
 
     def _apply_axis_direction(
-        self, position: Sequence[int] | Mapping[str | int]
+        self, position: list[int] | tuple[int] | Mapping[str | int]
     ) -> list[int] | Mapping[str | int]:
-        if isinstance(position, Sequence):
-            position = [
+        if isinstance(position, (list, tuple)):
+            return [
                 pos * ax_dir
                 for pos, ax_dir in zip(position, self.axis_direction.values())
             ]
-            return dict(zip(self.axis_names, position))
         if isinstance(position, Mapping):
             try:
                 return {

src/openflexure_microscope_server/things/stage/dummy.py

@@ -36,6 +36,13 @@ class DummyStage(BaseStage):
     def __exit__(self, _exc_type, _exc_value, _traceback):
         """Nothing to do when the Thing context manager is closed."""
 
+    axis_direction = lt.ThingSetting(
+        initial_value={"x": -1, "y": 1, "z": 1},
+        model=Mapping[str, int],
+        readonly=True,
+    )
+    """Used to convert coordinates between the program frame and the hardware frame."""
+
     def _hardware_move_relative(
         self,
         cancel: lt.deps.CancelHook,

src/openflexure_microscope_server/things/stage/sangaboard.py

@@ -69,6 +69,7 @@ class SangaboardThing(BaseStage):
     axis_direction = lt.ThingSetting(
         initial_value={"x": -1, "y": 1, "z": -1},
         model=Mapping[str, int],
+        readonly=True,
     )
     """Used to convert coordinates between the program frame and the hardware frame."""