feat(ui): implement save directory browse button and pre-detection check

- Add a 'Browse...' button to the Connection Status panel in StatusTab.qml.
- Check if save directory is set before wafer detection in HomePage.qml, prompting the user if empty.
- Resolve QML Connections warning by renaming onLogMessageEmitted to onLogMessage.
- Remove temporary debug stack traces from device_controller.py.

src/pygui/ISC/HomePage.qml

@@ -2,6 +2,7 @@ import QtQuick
 import QtQuick.Controls
 import QtQuick.Layouts
 import ISC
+import QtQuick.Dialogs
 
 // ===== Home Workspace Shell =====
 Rectangle {
@@ -59,6 +60,26 @@ Rectangle {
        }
    }
 
+    function cleanFolderUrl(url) {
+        return decodeURIComponent(String(url).replace(/^file:\/\//, ""))
+    }
+
+    function _doDetect() {
+        root.memoryRead = false
+        streamController.setMode("review")
+        streamController.stopStream()
+        deviceController.detectWafer()
+    }
+
+    FolderDialog {
+        id: saveDirDialog
+        title: "Choose a folder to save Data"
+        onAccepted: {
+            deviceController.setSaveDataDir(root.cleanFolderUrl(selectedFolder))
+            root._doDetect()
+        }
+    }
+
     // ===== Main Two-Column Layout ======
     RowLayout {
         anchors.fill: parent
@@ -106,10 +127,11 @@ Rectangle {
                             root.selectedSideActionIndex = index
                             root.selectedTabIndex = 0          // always jump to Status tab
                             if (index === 0) {
-                                root.memoryRead = false
+                                if (!deviceController.saveDataDir) {
-                                streamController.setMode("review")
+                                    saveDirDialog.open()
-                                streamController.stopStream()
+                                    return
-                                deviceController.detectWafer()
+                                }
+                                root._doDetect()
                             }
                             else if (index === 1) {
                                 streamController.setMode("review")

src/pygui/ISC/Tabs/StatusTab.qml

@@ -19,11 +19,6 @@ ColumnLayout {
     property alias waferCycles: waferCycles.text
     property bool waferDetected: false
 
-    // Latches true once any operation starts (or a previous session is
-    // restored) and never resets, so the status panel stays visible even
-    // when a detect finds no wafer.
-    property bool statusActive: false
-
     // Data summary after parse
     property int dataRows: 0
     property int dataCols: 0
@@ -45,31 +40,22 @@ ColumnLayout {
 
     FolderDialog {
         id: saveDirDialog
-        title: "Choose CSV Save Folder"
+        title: "Choose a folder to save."
         onAccepted: {
             deviceController.setSaveDataDir(root.cleanFolderUrl(selectedFolder))
             root.parseAndSavePendingRead()
         }
     }
 
-    // ===== Empty state — nothing shown until detect fires =====
-    Item {
-        Layout.fillWidth: true
-        Layout.fillHeight: true
-        visible: !root.statusActive
-    }
-
-    // ===== Results area (shown once detect/operation runs) =====
     ColumnLayout {
         Layout.fillWidth: true
         Layout.fillHeight: true
-        visible: root.statusActive
         spacing: Theme.rightPaneGap
 
         // --- Connection Status ---
         Rectangle {
             Layout.fillWidth: true
-            Layout.preferredHeight: 86
+            Layout.preferredHeight: 92
             color: Theme.cardBackground
             border.color: {
                 if (deviceController.connectionStatus === "Connected") return Theme.statusSuccessColor
@@ -102,13 +88,44 @@ ColumnLayout {
                     Layout.fillWidth: true
                 }
 
-                Text {
+                RowLayout {
-                    text: "Save dir: " + deviceController.saveDataDir
-                    color: Theme.bodyColor
-                    font.pixelSize: 12
-                    opacity: 0.7
-                    elide: Text.ElideMiddle
                     Layout.fillWidth: true
+                    spacing: 8
+                    Layout.alignment: Qt.AlignVCenter
+
+                    Text {
+                        text: "Save dir: " + (deviceController.saveDataDir || "None selected")
+                        color: Theme.bodyColor
+                        font.pixelSize: 12
+                        opacity: 0.7
+                        elide: Text.ElideMiddle
+                        Layout.fillWidth: true
+                        Layout.alignment: Qt.AlignVCenter
+                    }
+
+                    Button {
+                        id: browseBtn
+                        text: "BROWSE..."
+                        font.pixelSize: 9
+                        font.weight: Font.Medium
+                        implicitHeight: 20
+                        implicitWidth: 65
+                        hoverEnabled: true
+                        background: Rectangle {
+                            color: parent.hovered ? Theme.buttonNeutralHover : Theme.buttonNeutralBackground
+                            border.color: Theme.cardBorder
+                            border.width: 1
+                            radius: Theme.radiusSm
+                        }
+                        contentItem: Text {
+                            text: parent.text
+                            color: Theme.bodyColor
+                            font: parent.font
+                            horizontalAlignment: Text.AlignHCenter
+                            verticalAlignment: Text.AlignVCenter
+                        }
+                        onClicked: saveDirDialog.open()
+                    }
                 }
             }
         }
@@ -318,15 +335,21 @@ ColumnLayout {
 
     // --- Signal Handlers ---
      Connections {
-         target: deviceController
+        target: deviceController
-         // Any operation start (detect/read/erase/debug) latches the panel on.
-         function onPortsUpdated() {
-             if (deviceController.operationInProgress)
-                 root.statusActive = true
-         }
 
-         function onDetectResult(result) {
+        function onLogMessage(message) {
-             root.statusActive = true
+            if (message == "CHOOSE_SAVE_DIR"){
+                saveDirDialog.open()
+            }
+        }
+        
+           // Any operation start (detect/read/erase/debug) latches the panel on.
+           function onPortsUpdated() {
+               // Status tab always visible now
+           }
+
+
+          function onDetectResult(result) {
              if (result && result.familyCode) {
                  root.waferDetected = true
                  waferInfoFamily.text = result.familyCode
@@ -342,7 +365,6 @@ ColumnLayout {
              // Show restored wafer info if available
              var info = deviceController.lastWaferInfo
              if (info && info.length > 0) {
-                 root.statusActive = true
                  root.waferDetected = true
                  waferInfoFamily.text = info[0] || "—"
                  waferSerial.text     = info[1] || "—"
@@ -352,7 +374,6 @@ ColumnLayout {
              }
              // Show data summary if data was previously parsed
              if (deviceController.dataRowCount > 0) {
-                 root.statusActive = true
                  root.dataParsed = true
                  root.dataRows = deviceController.dataRowCount
                  root.dataCols = deviceController.dataColCount

src/pygui/backend/controllers/device_controller.py

@@ -90,6 +90,10 @@ class DeviceController(QObject):
         self._detectFinished.connect(self._handle_detect_finished, Qt.ConnectionType.QueuedConnection)
         self._readFinished.connect(self._handle_read_finished, Qt.ConnectionType.QueuedConnection)
 
+        root_logger = logging.getLogger()
+        root_logger.addHandler(QmlActivityLogHandler(self))
+        root_logger.setLevel(logging.INFO)
+
     # ---- Properties ----
     @Property(list, notify=portsUpdated)
     def availablePorts(self) -> list[str]:
@@ -538,3 +542,14 @@ class DeviceController(QObject):
             "runtime": info.runtime,
             "cycleCount": info.cycle_count,
         }
+
+class QmlActivityLogHandler(logging.Handler):
+    def __init__(self, controller: DeviceController) -> None:
+        super().__init__()
+        self._controller = controller
+    def emit(self, record: logging.LogRecord) -> None:
+        timestamp = datetime.now().strftime("%H:%M:%S")
+        level = record.levelname
+        message = record.getMessage()
+        msg = f"[{timestamp}] {level}: {message}"
+        self._controller._append_log(msg)