fix: The QML cross-component id resolution for root.waferDetected was failing

silently. Exposing a proper waferDetected property on the Python
DeviceController ensures reliable gating, and resetting it on refresh
blocks the actions until the next successful detection.

src/pygui/ISC/Tabs/components/StatusActionsPanel.qml

@@ -44,7 +44,7 @@ ColumnLayout {
                 label: "READ MEMORY"
                 iconSource: "../icons/read.svg"
                 Layout.fillWidth: true
-                enabled: root.waferDetected
+                enabled: deviceController.waferDetected && !deviceController.operationInProgress
                 onClicked: deviceController.readMemoryAsync()
             }
 
@@ -53,7 +53,7 @@ ColumnLayout {
                 iconSource: "../icons/erase.svg"
                 Layout.fillWidth: true
                 destructive: true
-                enabled: root.waferDetected
+                enabled: deviceController.waferDetected && !deviceController.operationInProgress
                 onClicked: deviceController.eraseMemory(
                     deviceController.selectedPort)
             }
@@ -87,6 +87,7 @@ ColumnLayout {
                 label: "REFRESH SESSION"
                 iconSource: "../icons/refresh.svg"
                 Layout.fillWidth: true
+                enabled: !deviceController.operationInProgress
                 onClicked: deviceController.clearSession()
             }
 

src/pygui/backend/controllers/device_controller.py

@@ -38,6 +38,7 @@ class DeviceController(QObject):
     portsUpdated = Signal(list)
     connectionStatusChanged = Signal()
     operationInProgressChanged = Signal()
+    waferDetectedChanged = Signal()
     selectedPortChanged = Signal()
     detectResult = Signal(object)  # WaferInfo dict or None
     readResult = Signal(dict)  # {"success": bool, "bytes": int} or {"error": str}
@@ -77,6 +78,7 @@ class DeviceController(QObject):
         #   → denied = safe default. Called by P2.1.
         #   See docs/pending/license-gating-plan.md §1.2.
         self._last_wafer_info: dict[str, Any] = {}
+        self._wafer_detected: bool = False
         self._last_csv_path: str = ""
         self._selected_port: str = ""
         self._data_row_count: int = 0
@@ -212,6 +214,17 @@ class DeviceController(QObject):
             info.get("cycleCount", 0),
         ]
 
+    @Property(bool, notify=waferDetectedChanged)
+    def waferDetected(self) -> bool:
+        """Whether a wafer is currently detected and ready for read/erase."""
+        return self._wafer_detected
+
+    def _set_wafer_detected(self, detected: bool) -> None:
+        if self._wafer_detected != detected:
+            self._wafer_detected = detected
+            self.waferDetectedChanged.emit()
+
+
     @Property(object, notify=detectResult)
     def dataModel(self) -> TemperatureTableModel:
         """QAbstractTableModel for the parsed temperature data table."""
@@ -276,6 +289,7 @@ class DeviceController(QObject):
         self._set_connection_status("Disconnected")
         self._selected_port = ""
         self._last_wafer_info = {}
+        self._set_wafer_detected(False)
         self._data_row_count = 0
         self._data_col_count = 0
         self._raw_bytes = None
@@ -366,6 +380,7 @@ class DeviceController(QObject):
                 wafer_dict = self._wafer_info_to_dict(info)
                 self._selected_port = port or ""
                 self._last_wafer_info = wafer_dict
+                self._set_wafer_detected(True)
                 self._set_connection_status("Connected")
                 self.detectResult.emit(wafer_dict)
                 self.selectedPortChanged.emit()
@@ -375,6 +390,7 @@ class DeviceController(QObject):
                 self._set_connection_status("Disconnected")
                 self._append_log("No wafer detected on any port")
                 self._last_wafer_info = {}
+                self._set_wafer_detected(False)
                 self.detectResult.emit(None)
                 self.selectedPortChanged.emit()
         finally: