feat: add recording toggle, stream stats UI

tests/test_session_controller.py

@@ -64,6 +64,26 @@ def test_compare_files_integration(controller):
     assert "series_a" in args
     assert "series_b" in args
 
+def test_recording_toggle(controller, tmp_path):
+    csv_path = str(tmp_path / "rec" / "live_test.csv")
+    controller.startRecording(csv_path, "SN123")
+    assert controller.recording == True
+
+    controller.stopRecording()
+    assert controller.recording == False
+
+    # Header written with wafer serial
+    content = open(csv_path).read()
+    assert "Wafer ID=SN123" in content
+
+def test_resync_count_default(controller):
+    # No active reader -> zero
+    assert controller.resyncCount == 0
+
+    controller._reader = MagicMock(resync_count=7)
+    assert controller.resyncCount == 7
+    controller._reader = None
+
 def test_split_data_integration(controller):
     # Mock the splitResult signal
     mock_slot = MagicMock()