Remove every deprecated member for 2.0 (#821)

[Rafael-SOWNet]

Part of #821 — the "remove deprecated functions" half. 2.0 follows semantic versioning, so all 28 members carrying [Obsolete] are gone, along with the call sites and the suppressions that kept them alive. The whole solution now builds with no CS0618 anywhere, and no pragma disabling it.

One replacement did not exist

MathS.Compute.DefiniteIntegral was deprecated in favour of "non-static methods at Entity" — and there was no Entity.DefiniteIntegral. Every other member of that group had a counterpart; this one did not. Removing it as it stood would have taken numeric definite integration out of the library with nothing to replace it.

So Entity.DefiniteIntegral(x, from, to, stepCount = 100) is added here, in real and complex bound overloads, and the three tests move onto it.

The library was using its own deprecated API

Two places, both behind #pragma warning disable CS0618:

• MatrixOperations.Concat indexed the obsolete Matrix.Shape. It now asks RowCount/ColumnCount through a small local helper, since the axis is computed rather than literal.
• CompilationProtocol carried six obsolete converter delegates plus the branches consulting them — with a comment saying to remove them when the converters went.

Corrections to what I told this issue

I reported the opposite of that last point, and it is worth being explicit about why. I checked for CS0618 warnings, found none, and concluded the library did not call its own deprecated API. The absence was manufactured by those pragmas. An absence of warnings proves nothing where warnings are suppressed — the pragma was the thing to grep for, and I did not.

The same mistake inflated my call-site count three times over:

• The obsolete Matrices.Matrix is the Entity[,] overload, not the (rows, columns, params) one the tests actually use.
• The obsolete Interval overloads live in MathS.**Matrices**, not MathS.Sets.
• MathS.Derivative/Integral/Limit are node constructors and are not deprecated at all — entirely distinct from MathS.Compute.* of the same names.

Nineteen call sites was wrong: there were five, plus the two suppressed regions inside the library.

What moved

removed	use instead
MathS.Matrices.Matrix(Entity[,])	MathS.Matrix
MathS.Matrices.Vector(params Entity[])	MathS.Vector
MathS.Matrices.MatrixMultiplication, DotProduct	operator *
MathS.Matrices.ScalarProduct(a, b)	a.T * b
MathS.Matrices.Interval(...) ×2	MathS.Interval
MathS.Compute.Derivative ×2	expr.Differentiate(x)
MathS.Compute.Integral ×2	expr.Integrate(x)
MathS.Compute.Limit ×2	expr.Limit(x, to)
MathS.Compute.DefiniteIntegral ×3	expr.DefiniteIntegral(x, from, to) — new
Entity.Derive, "...".Derive	Differentiate
Entity.Matrix.Shape	RowCount, ColumnCount
Setting.Global, RollBackToDefault	Setting.Set in a using
CompilationProtocol's six converter delegates	inherit and override the methods
CompilationProtocolBuiltinConstantConverters	CompilationProtocol

DefaultConverters.cs is deleted outright, being a single obsolete class with no other contents.

Tests

5928 passing, 0 failed, 14 skipped. F# 130 passing. No behavioural change — the removed members were forwarders or duplicates, and everything they forwarded to is unchanged.

BREAKING-CHANGES.md carries the full table and the note about the missing replacement.

Still open on #821

The other half — "redesign all APIs for consistency and correctness" — is untouched here. That wants your direction on what counts as inconsistent, and it is a much larger conversation than deleting what was already marked for deletion.

🤖 Generated with Claude Code