Make UI event-driven, heat maps at 10Hz from tick loop

- Heat maps fed from tick loop via BeginInvoke (10Hz, one column per tick)
- BLE label updates on ConnectionChanged event (was 4Hz poll)
- Recv gauges update on StrengthChanged event (B1 notifications)
- Button states refreshed via RefreshButtonStates on all state changes
- Status timer reduced from 250ms to 1s — only music label + tray icon
- Eliminates 4Hz choppy polling

MainForm.cs

@@ -260,7 +260,7 @@ public class MainForm : Form
         _tray.ContextMenuStrip.Items.Add("Exit", null, (_, _) => ExitFromTray());
         _tray.DoubleClick += (_, _) => ShowFromTray();
 
-        _statusTimer = new System.Windows.Forms.Timer { Interval = 250 };
+        _statusTimer = new System.Windows.Forms.Timer { Interval = 1000 };
         _statusTimer.Tick += OnStatusTick;
         _statusTimer.Start();
 
@@ -269,6 +269,8 @@ public class MainForm : Form
         Resize += OnResize;
 
         _server.ClientChanged += OnWsClientChanged;
+        _device.ConnectionChanged += OnDeviceConnectionChanged;
+        _device.StrengthChanged += OnDeviceStrengthChanged;
     }
 
     async void OnLoad(object? sender, EventArgs e)
@@ -297,6 +299,14 @@ public class MainForm : Form
                     var frame = B0.Build(0, modeA, modeB, valA, valB, freqA, intA, freqB, intB);
                     await _device.SendB0(frame);
                 }
+                if (!IsDisposed)
+                {
+                    BeginInvoke(() =>
+                    {
+                        _heatA.AddTick(freqA, intA, _state.LastActiveA);
+                        _heatB.AddTick(freqB, intB, _state.LastActiveB);
+                    });
+                }
             }
             catch (Exception ex)
             {
@@ -368,31 +378,44 @@ public class MainForm : Form
         BeginInvoke(() =>
         {
             _lblWs.Text = connected ? "WS: client connected" : "WS: idle";
-            _btnTest.Enabled = !connected && !IsTestRunning;
-            _btnMusic.Enabled = !connected && !_isMusicRunning;
+            RefreshButtonStates();
             UpdateTrayIcon();
         });
     }
 
+    void OnDeviceConnectionChanged(bool connected)
+    {
+        if (IsDisposed) return;
+        BeginInvoke(() =>
+        {
+            _lblBle.Text = connected
+                ? $"BLE: connected ({_device.DeviceName})"
+                : "BLE: disconnected";
+            _btnConnect.Enabled = !connected;
+            RefreshButtonStates();
+        });
+    }
+
+    void OnDeviceStrengthChanged(int a, int b)
+    {
+        if (IsDisposed) return;
+        BeginInvoke(() =>
+        {
+            _gaugeRecvA.Value = Math.Clamp(a, 0, 200);
+            _gaugeRecvB.Value = Math.Clamp(b, 0, 200);
+        });
+    }
+
+    void RefreshButtonStates()
+    {
+        _btnTest.Enabled = !_server.HasClient && !IsTestRunning;
+        _btnMusic.Enabled = !_server.HasClient && !_isMusicRunning;
+        _btnStop.Enabled = true;
+    }
+
     void OnStatusTick(object? sender, EventArgs e)
     {
         if (IsDisposed) return;
-        _lblBle.Text = _device.IsConnected
-            ? $"BLE: connected ({_device.DeviceName})"
-            : "BLE: disconnected";
-        _heatA.AddTick(
-            _state.LastFreqA ?? Array.Empty<byte>(),
-            _state.LastIntA ?? Array.Empty<byte>(),
-            _state.LastActiveA);
-        _heatB.AddTick(
-            _state.LastFreqB ?? Array.Empty<byte>(),
-            _state.LastIntB ?? Array.Empty<byte>(),
-            _state.LastActiveB);
-        _gaugeRecvA.Value = Math.Clamp(_device.StrengthA, 0, 200);
-        _gaugeRecvB.Value = Math.Clamp(_device.StrengthB, 0, 200);
-        _btnTest.Enabled = !_server.HasClient && !IsTestRunning;
-        _btnMusic.Enabled = !_server.HasClient && !_isMusicRunning;
-        _btnStop.Enabled = true;
 
         if (_isMusicRunning && _musicStopwatch != null)
         {
@@ -457,7 +480,7 @@ public class MainForm : Form
         BeginInvoke(() =>
         {
             IsTestRunning = false;
-            _btnTest.Enabled = !_server.HasClient;
+            RefreshButtonStates();
         });
     }
 
@@ -525,8 +548,7 @@ public class MainForm : Form
             {
                 _lblTrack.Text = $"Analysis failed: {ex.Message}";
                 _isMusicRunning = false;
-                _btnMusic.Enabled = !_server.HasClient;
-                _btnTest.Enabled = !_server.HasClient && !IsTestRunning;
+                RefreshButtonStates();
             });
             return;
         }
@@ -578,7 +600,7 @@ public class MainForm : Form
             if (!IsDisposed)
             {
                 _lblTrack.Text = "";
-                _btnMusic.Enabled = !_server.HasClient;
+                RefreshButtonStates();
             }
         }
     }