Reintroduce recactive button state for background detect

src/openflexure_microscope_server/things/scan_workflows.py

@@ -625,12 +625,14 @@ class HistoScanWorkflow(RectGridWorkflow[HistoScanSettingsModel]):
             can_terminate=False,
             notify_on_success=True,
             success_message="Background image has been updated",
+            update_interface_on_response=True,
         )
         check_bg_button = action_button_for(
             self,
             "check_background",
             poll_interval=0.1,
             submit_label="Check Current Image",
+            disabled=not self._background_detector.ready,
             can_terminate=False,
             notify_on_success=True,
             response_is_success_message=True,

src/openflexure_microscope_server/ui.py

@@ -158,6 +158,9 @@ class ActionButton(BaseModel):
     button_primary: bool = True
     """Specify whether the button is styled as a primary button."""
 
+    disabled: bool = False
+    """Specify whether the button is disabled."""
+
     modal_progress: bool = False
     """Specify whether to show a progress modal."""
 
@@ -180,6 +183,12 @@ class ActionButton(BaseModel):
     success_message: str = "Success!"
     """The message to show on successful completion."""
 
+    update_interface_on_response: bool = False
+    """If True the action button emits a requestUpdate signal when completed.
+
+    Downstream components can subscribe to this and request an update.
+    """
+
 
 def action_button_for(thing: lt.Thing, action_name: str, **kwargs: Any) -> ActionButton:
     """Create a ActionButton data for the specified Thing Action.