Refactor and enhance various channel indicators for improved performance and stability

- Updated Codacy instructions to streamline usage guidelines.
- Refactored Bbands class to utilize ArrayPool for memory management, preventing stack overflow on large series.
- Changed Fcb class to use long for monotonic deques to avoid truncation issues.
- Enhanced Kchannel class to ensure safe defaults for non-finite values.
- Improved Maenv class to prevent double-priming during calculations.
- Modified Mmchannel class to ensure non-negative buffer indices and removed unnecessary state tracking.
- Updated Pchannel class to correctly reference IsHot state.
- Refined Regchannel class to avoid double-processing during calculations.
- Enhanced Starchannel class to sanitize non-finite values during calculations.
- Adjusted Stbands.Quantower.cs to allow finer control over multiplier precision.
- Updated Ubands class to only update last valid values on new bars.
- Modified Uchannel.Quantower.cs to allow for finer multiplier precision.
- Enhanced Vwapbands classes to include standard deviation calculations and ensure consistent array lengths.
- Refactored Vwapsd classes to include standard deviation outputs and ensure consistent array lengths.
- Updated MonotonicDeque to use long for indices to prevent overflow.
- Improved Mdape class to handle zero actual values with a substitute value for error calculation.
- Enhanced Rae class to ensure correct state management during updates.
- Refined Wmape class to simplify the logic for finding last valid actual and predicted values.
- Updated Cmf.Quantower classes to ensure MinHistoryDepths reflects the current period.

lib/errors/mdape/Mdape.Tests.cs

@@ -309,17 +309,18 @@ public class MdapeTests
     }
 
     [Fact]
-    public void Calculate_ZeroActual_ReturnsZeroError()
+    public void Calculate_ZeroActual_UsesSubstituteValue()
     {
-        // When actual is zero or near-zero, should return 0 error (epsilon protection)
+        // When actual is zero or near-zero, implementation substitutes 1.0 fallback
+        // to avoid division by zero (epsilon protection means substitute, not return 0)
         var mdape = new Mdape(3);
 
-        mdape.Update(0.0, 10);
-        mdape.Update(0.0, 20);
-        mdape.Update(0.0, 30);
+        mdape.Update(0.0, 10);  // actual=1.0 (substituted), pred=10 → |1-10|/1 * 100 = 900%
+        mdape.Update(0.0, 20);  // actual=1.0 (substituted), pred=20 → |1-20|/1 * 100 = 1900%
+        mdape.Update(0.0, 30);  // actual=1.0 (substituted), pred=30 → |1-30|/1 * 100 = 2900%
 
-        // With epsilon protection, all errors are 0
-        Assert.Equal(0.0, mdape.Last.Value, Precision);
+        // Median of [900, 1900, 2900] = 1900
+        Assert.Equal(1900.0, mdape.Last.Value, Precision);
     }
 
     [Fact]
@@ -361,4 +362,4 @@ public class MdapeTests
 
         Assert.Equal(mdape1.Last.Value, mdape2.Last.Value, Precision);
     }
-}
+}

lib/errors/mdape/Mdape.cs

@@ -74,9 +74,12 @@ public sealed class Mdape : AbstractBase
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private TValue UpdateCore(DateTime time, double actualVal, double predictedVal, bool isNew)
     {
-        if (!double.IsFinite(actualVal))
+        // Validate actual: must be finite AND have sufficient magnitude (matches Batch logic)
+        if (!double.IsFinite(actualVal) || Math.Abs(actualVal) < 1e-10)
         {
-            actualVal = double.IsFinite(_state.LastValidActual) ? _state.LastValidActual : 1.0;
+            actualVal = double.IsFinite(_state.LastValidActual) && Math.Abs(_state.LastValidActual) >= 1e-10
+                ? _state.LastValidActual
+                : 1.0;
         }
         else
         {
@@ -92,10 +95,10 @@ public sealed class Mdape : AbstractBase
             _state.LastValidPredicted = predictedVal;
         }
 
-        // Calculate absolute percentage error
+        // Calculate absolute percentage error (absActual guaranteed >= 1e-10 by validation above)
         double absActual = Math.Abs(actualVal);
         double absError = Math.Abs(actualVal - predictedVal);
-        double percentageError = absActual > 1e-10 ? (absError / absActual) * 100.0 : 0.0;
+        double percentageError = (absError / absActual) * 100.0;
 
         if (isNew)
         {