Fix Send gauges showing intensity, zero when idle

- Send gauges now show waveform intensity (0-100) not strength ceiling
- State.LastIntensityA/B tracks average intensity per tick
- Zero when no pattern/stream active (was 25 due to IntensityOff 101 sentinel)
- Recv gauges unchanged (device-reported strength 0-200)

MainForm.cs

@@ -142,7 +142,7 @@ public class MainForm : Form
             Location = new Point(72, 160),
             Size = new Size(332, 20),
             Minimum = 0,
-            Maximum = 200,
+            Maximum = 100,
             Style = ProgressBarStyle.Continuous
         };
         _lblSendB = new Label
@@ -157,7 +157,7 @@ public class MainForm : Form
             Location = new Point(72, 184),
             Size = new Size(332, 20),
             Minimum = 0,
-            Maximum = 200,
+            Maximum = 100,
             Style = ProgressBarStyle.Continuous
         };
         _lblRecvA = new Label
@@ -357,8 +357,8 @@ public class MainForm : Form
         _lblBle.Text = _device.IsConnected
             ? $"BLE: connected ({_device.DeviceName})"
             : "BLE: disconnected";
-        _gaugeSendA.Value = Math.Clamp(_state.LastSentA, 0, 200);
-        _gaugeSendB.Value = Math.Clamp(_state.LastSentB, 0, 200);
+        _gaugeSendA.Value = Math.Clamp(_state.LastIntensityA, 0, 100);
+        _gaugeSendB.Value = Math.Clamp(_state.LastIntensityB, 0, 100);
         _gaugeRecvA.Value = Math.Clamp(_device.StrengthA, 0, 200);
         _gaugeRecvB.Value = Math.Clamp(_device.StrengthB, 0, 200);
         _btnTest.Enabled = !_server.HasClient && !IsTestRunning;