Fix heat map scaling, add per-channel amplifier

- Add per-channel amplifier (0-100, 1.0x to 10.0x) applied to intensity
  before limiter gates strength
- Fix heat map scaling: use LimitScaleA/B (valA/DesiredA ratio) instead
  of valA/200 — was capping colors at green, never reaching orange
- Scale heat map intensity by limiter ratio so colors reflect actual
  output after limiter
- Remove dead LastIntensityA/B field (replaced by heat map scaling)
- Amp trackbars: 0=1.0x, 100=10.0x, integer value labels
- Close button quits app instead of hiding to tray

State.cs

@@ -17,7 +17,7 @@ public class State
 
     public int ActualA, ActualB;
     public int LastSentA, LastSentB;
-    public int LastIntensityA, LastIntensityB;
+    public double LimitScaleA, LimitScaleB;
     public byte[]? LastFreqA, LastIntA, LastFreqB, LastIntB;
     public bool LastActiveA, LastActiveB;
 
@@ -26,6 +26,8 @@ public class State
     public LimitMode LimitModeA = LimitMode.Clamp;
     public LimitMode LimitModeB = LimitMode.Clamp;
     public bool SwapChannels;
+    public double AmpA = 1.0;
+    public double AmpB = 1.0;
 
     public void SetLimitA(int max, LimitMode mode)
     {
@@ -47,6 +49,24 @@ public class State
         }
     }
 
+    public void SetAmpA(double amp)
+    {
+        lock (Lock)
+        {
+            AmpA = Math.Clamp(amp, 0.1, 10.0);
+            DirtyA = true;
+        }
+    }
+
+    public void SetAmpB(double amp)
+    {
+        lock (Lock)
+        {
+            AmpB = Math.Clamp(amp, 0.1, 10.0);
+            DirtyB = true;
+        }
+    }
+
     public bool IsSignaling
     {
         get
@@ -115,20 +135,31 @@ public class State
             var valB  = ApplyLimit(DesiredB, MaxB, LimitModeB);
             LastSentA = valA;
             LastSentB = valB;
+            LimitScaleA = DesiredA > 0 ? (double)valA / DesiredA : 0;
+            LimitScaleB = DesiredB > 0 ? (double)valB / DesiredB : 0;
             DirtyA = false;
             DirtyB = false;
 
             bool hasA = !StreamA.IsEmpty || (LoopFreqA != null && LoopIntA != null);
             bool hasB = !StreamB.IsEmpty || (LoopFreqB != null && LoopIntB != null);
-            var (freqA, intA) = PopWave(StreamA, LoopFreqA, LoopIntA);
-            var (freqB, intB) = PopWave(StreamB, LoopFreqB, LoopIntB);
+            var (freqA, intARaw) = PopWave(StreamA, LoopFreqA, LoopIntA);
+            var (freqB, intBRaw) = PopWave(StreamB, LoopFreqB, LoopIntB);
+
+            // Apply amplifier to intensity, clamp to 0-100
+            var ampA = AmpA;
+            var ampB = AmpB;
+            var intA = new byte[4];
+            var intB = new byte[4];
+            for (int i = 0; i < 4; i++)
+            {
+                intA[i] = (byte)Math.Clamp((int)Math.Round(intARaw[i] * ampA), 0, 100);
+                intB[i] = (byte)Math.Clamp((int)Math.Round(intBRaw[i] * ampB), 0, 100);
+            }
 
             LastActiveA = hasA;
             LastActiveB = hasB;
             LastFreqA = freqA; LastIntA = intA;
             LastFreqB = freqB; LastIntB = intB;
-            LastIntensityA = hasA ? (intA[0] + intA[1] + intA[2] + intA[3]) / 4 : 0;
-            LastIntensityB = hasB ? (intB[0] + intB[1] + intB[2] + intB[3]) / 4 : 0;
 
             if (SwapChannels)
             {
@@ -140,7 +171,7 @@ public class State
                 (LastFreqA, LastFreqB) = (LastFreqB, LastFreqA);
                 (LastIntA, LastIntB) = (LastIntB, LastIntA);
                 (LastActiveA, LastActiveB) = (LastActiveB, LastActiveA);
-                (LastIntensityA, LastIntensityB) = (LastIntensityB, LastIntensityA);
+                (LimitScaleA, LimitScaleB) = (LimitScaleB, LimitScaleA);
             }
 
             return (modeA, valA, modeB, valB, freqA, intA, freqB, intB);