chore: repo cleanup and code quality improvements

- Remove global.json (SDK pinning unnecessary)

- Remove nuget.config, move MyGet source to .csproj RestoreAdditionalProjectSources

- Gitignore ndepend/ entirely, move badges to docs/img/

- Update README.md and docs/ndepend.md badge paths

- Add NDepend project property to QuanTAlib.slnx

- Expand .editorconfig ReSharper/diagnostic suppressions

- Use ArgumentOutOfRangeException instead of ArgumentException

- Use discard _ for unused event sender parameters

- Remove quantalib.code-workspace and sonar-suppressions.json

- Add filter signature SVGs

lib/statistics/cointegration/Cointegration.cs

@@ -114,15 +114,11 @@ public sealed class Cointegration : AbstractBase
     {
         return Update(new TValue(DateTime.MinValue, seriesA), new TValue(DateTime.MinValue, seriesB), isNew);
     }
-
-    /// <inheritdoc/>
     /// <remarks>Not supported for bi-input indicator. Use Update(seriesA, seriesB) instead.</remarks>
     public override TValue Update(TValue input, bool isNew = true)
     {
         throw new NotSupportedException("Cointegration requires two inputs (seriesA and seriesB). Use Update(seriesA, seriesB).");
     }
-
-    /// <inheritdoc/>
     /// <remarks>Not supported for bi-input indicator. Use Calculate(seriesA, seriesB, period) instead.</remarks>
     public override TSeries Update(TSeries source)
     {
@@ -402,8 +398,6 @@ public sealed class Cointegration : AbstractBase
             _sumDelta2 = FusedMultiplyAdd(delta, delta, _sumDelta2);
         }
     }
-
-    /// <inheritdoc/>
     public override void Prime(ReadOnlySpan<double> source, TimeSpan? step = null)
     {
         throw new NotSupportedException("Cointegration requires two inputs.");