Refactor error handling and calculations in TheilU, Wmape, and TukeyBiweight classes; update buffer handling for consistency

- Updated buffer handling in TheilU and Wmape classes to ensure consistency after adding new values.
- Changed the resync interval constant in TukeyBiweight for better clarity.
- Refactored state structures to record structs in Gauss, Hann, Hp, Hpf, Kalman, Loess, Notch, and other filter classes for improved performance and readability.
- Enhanced numerical stability in Mama class calculations using Fused Multiply-Add (FMA) for precision.
- Added comprehensive tests for Atan2 validation to compare .NET's Math.Atan2 with PineScript's implementation, ensuring accuracy across various edge cases.
- Updated NDepend badges to reflect changes in classes, methods, and lines of code.

lib/trends_IIR/frama/Frama.cs

@@ -29,7 +29,7 @@ public sealed class Frama : ITValuePublisher
     private readonly TValuePublishedHandler _handler;
 
     [StructLayout(LayoutKind.Sequential)]
-    private struct State
+    private record struct State
     {
         public double Frama;
         public double LastHigh;

lib/trends_IIR/hema/Hema.cs

@@ -30,7 +30,7 @@ public sealed class Hema : AbstractBase
     private const double Ln2 = 0.693147180559945309417232121458176568;
 
     [StructLayout(LayoutKind.Sequential)]
-    private struct State
+    private record struct State
     {
         public double EmaSlowRaw;
         public double EmaFastRaw;

lib/trends_IIR/mama/Mama.cs

@@ -210,9 +210,12 @@ public sealed class Mama : AbstractBase
             double alpha = _scaledFastLimit / delta;
             alpha = Math.Clamp(alpha, _slowLimit, _fastLimit);
 
-            // Final indicators
-            _state.Mama = alpha * _priceBuffer[^1] + (1.0 - alpha) * _p_state.Mama;
-            _state.Fama = FamaAlphaFactor * alpha * _state.Mama + (1.0 - FamaAlphaFactor * alpha) * _p_state.Fama;
+            // Final indicators (using FMA for precision)
+            double decay = 1.0 - alpha;
+            _state.Mama = Math.FusedMultiplyAdd(_p_state.Mama, decay, alpha * _priceBuffer[^1]);
+            double famaAlpha = FamaAlphaFactor * alpha;
+            double famaDecay = 1.0 - famaAlpha;
+            _state.Fama = Math.FusedMultiplyAdd(_p_state.Fama, famaDecay, famaAlpha * _state.Mama);
         }
         else
         {
@@ -442,9 +445,12 @@ public sealed class Mama : AbstractBase
                 double alpha = scaledFastLimit / delta;
                 alpha = Math.Clamp(alpha, slowLimit, fastLimit);
 
-                // Final indicators
-                mama = alpha * priceBuffer[bufferIdx] + (1.0 - alpha) * p_mama;
-                fama = FamaAlphaFactor * alpha * mama + (1.0 - FamaAlphaFactor * alpha) * p_fama;
+                // Final indicators (using FMA for precision)
+                double decay = 1.0 - alpha;
+                mama = Math.FusedMultiplyAdd(p_mama, decay, alpha * priceBuffer[bufferIdx]);
+                double famaAlpha = FamaAlphaFactor * alpha;
+                double famaDecay = 1.0 - famaAlpha;
+                fama = Math.FusedMultiplyAdd(p_fama, famaDecay, famaAlpha * mama);
 
                 // Update previous state
                 p_i2 = i2;