feat(generator): add SEM002 metadata validation; refresh stale generator output

- Adds DimensionsMetadata.Validate() and a SEM002 Roslyn diagnostic so
  malformed entries in dimensions.json (missing name/symbol, empty
  availableUnits, duplicate type names, no vector forms declared)
  surface in the build log instead of crashing the emit pass or dropping
  output silently. Pairs with the existing SEM001 (closes #60).
- Adds AnalyzerReleases.Shipped/Unshipped.md so SEM001/SEM002 satisfy
  RS2008 analyzer release tracking; the generator project now builds
  clean.
- Re-runs QuantitiesGenerator to refresh 132 committed .g.cs files that
  were stale relative to the V0 non-negativity / absolute V0-V0
  subtraction work merged in #66/#68. Diff is purely the documented
  #50/#52 changes (Vector0Guards.EnsureNonNegative in factories;
  same-type T.Abs subtraction replacing the old V1-typed result).
- CLAUDE.md: corrects the V0 invariant entry (constraints are enforced
  structurally, not yet declared in metadata), fixes the
  PhysicalConstants surface to match what's actually emitted (no
  Conversion sub-class), and lists the SEM00x diagnostics.

Author: claude

CLAUDE.md

@@ -51,19 +51,25 @@ These are now baked into the generator and enforced by tests. **Do not reopen wi
 1. **`V0 - V0` returns the same `V0` of `T.Abs(a - b)`.** Magnitude subtraction stays non-negative; signed subtraction must use the V1 form explicitly.
 2. **Dimensionless and angular quantities have both `Ratio` (V0) and `SignedRatio` (V1) bases.** Ratios that semantically must be non-negative (e.g. `RefractiveIndex`, `MachNumber`, `SpecificGravity`) are V0 overloads of `Ratio`.
 3. **Semantic overloads widen implicitly to their base, narrow explicitly from it.** A `Weight` is implicitly a `ForceMagnitude`; the reverse requires `Weight.From(forceMagnitude)` or an explicit cast.
-4. **Physical constraints come from per-dimension metadata.** Floors like absolute zero or non-negative frequency are declared in `dimensions.json` and the generator emits `ArgumentException`-throwing guards inside the `Create`/`From*` factories.
+4. **Physical constraints are enforced structurally via the V0 (magnitude) form.** `Vector0` factories run `Vector0Guards.EnsureNonNegative` and throw `ArgumentException` on a negative value. That covers absolute zero (Temperature is V0, so Kelvin must be ≥ 0), non-negative frequency, non-negative absolute pressure, etc. Strict-positive or upper-bound constraints are not yet declared in metadata (tracked separately).
 
 ### Physical constants
 
-`PhysicalConstants` is **generated** from `dimensions.json` (and a constants fixture). Public surface:
+`PhysicalConstants` is **generated** from `domains.json`. Public surface:
 
 ```csharp
+// Domain-grouped PreciseNumber values:
+PhysicalConstants.Fundamental.SpeedOfLight
+PhysicalConstants.Fundamental.PlanckConstant
+PhysicalConstants.AngularMechanics.DegreesPerRadian
+
+// Generic accessors that materialise into any T : INumber<T>:
 PhysicalConstants.Generic.SpeedOfLight<T>()
 PhysicalConstants.Generic.PlanckConstant<T>()
-PhysicalConstants.Conversion.FeetToMeters<T>()
+PhysicalConstants.Generic.DegreesPerRadian<T>()
 ```
 
-Use these accessors instead of hard-coded numerics. Backing values are stored as `PreciseNumber` and converted with `T.CreateChecked` per call.
+Backing values are stored as `PreciseNumber` and converted with `T.CreateChecked` per call.
 
 ### Operators and physics relationships
 
@@ -139,6 +145,9 @@ var converted = sourceString.As<SourceType, TargetType>();
 - Edit `Semantics.SourceGenerators/Metadata/dimensions.json` to add a dimension, vector form, semantic overload, or relationship.
 - Rebuild `Semantics.SourceGenerators` and the consuming `Semantics.Quantities` project; emitted files appear in `Semantics.Quantities/Generated/Semantics.SourceGenerators/<GeneratorName>/`.
 - Treat generator output as committed source. Diff it before commit so accidental regressions are visible.
+- Generator diagnostics:
+  - **SEM001** — a relationship in `dimensions.json` references a dimension that does not exist (typo or rename). The operator is silently dropped.
+  - **SEM002** — schema-level validation issue (missing `name`/`symbol`, empty `availableUnits`, duplicate type names, no vector forms declared).
 - See `docs/physics-generator.md` for the full schema and an end-to-end "add a dimension" walk-through.
 
 This file is the entry point. For deeper material:

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/AbsorbedDose.g.cs

@@ -22,6 +22,12 @@ public record AbsorbedDose<T> : PhysicalQuantity<AbsorbedDose<T>, T>, IVector0<A
 	/// </summary>
 	/// <param name="value">The value in Gray.</param>
 	/// <returns>A new <see cref="AbsorbedDose{T}"/> instance.</returns>
-	public static AbsorbedDose<T> FromGray(T value) => Create(value);
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static AbsorbedDose<T> FromGray(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
+/// <summary>
+	/// Subtracts two AbsorbedDose values, returning the absolute difference as a non-negative AbsorbedDose.
+	/// Magnitude subtraction stays a magnitude (per the unified-vector model).
+	/// </summary>
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static AbsorbedDose<T> operator -(AbsorbedDose<T> left, AbsorbedDose<T> right) => Create(T.Abs(left.Quantity - right.Quantity));
 };
 

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/AccelerationMagnitude.g.cs

@@ -22,11 +22,13 @@ public record AccelerationMagnitude<T> : PhysicalQuantity<AccelerationMagnitude<
 	/// </summary>
 	/// <param name="value">The value in MetersPerSecondSquared.</param>
 	/// <returns>A new <see cref="AccelerationMagnitude{T}"/> instance.</returns>
-	public static AccelerationMagnitude<T> FromMetersPerSecondSquared(T value) => Create(value);
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static AccelerationMagnitude<T> FromMetersPerSecondSquared(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 /// <summary>
-	/// Subtracts two AccelerationMagnitude values, returning a signed Acceleration1D result.
+	/// Subtracts two AccelerationMagnitude values, returning the absolute difference as a non-negative AccelerationMagnitude.
+	/// Magnitude subtraction stays a magnitude (per the unified-vector model).
 	/// </summary>
-	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static Acceleration1D<T> operator -(AccelerationMagnitude<T> left, AccelerationMagnitude<T> right) => Acceleration1D<T>.Create(left.Quantity - right.Quantity);
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static AccelerationMagnitude<T> operator -(AccelerationMagnitude<T> left, AccelerationMagnitude<T> right) => Create(T.Abs(left.Quantity - right.Quantity));
 /// <summary>
 	/// Multiplies AccelerationMagnitude by Mass to produce ForceMagnitude.
 	/// </summary>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/AcousticImpedance.g.cs

@@ -22,6 +22,12 @@ public record AcousticImpedance<T> : PhysicalQuantity<AcousticImpedance<T>, T>,
 	/// </summary>
 	/// <param name="value">The value in PascalSecondPerMeter.</param>
 	/// <returns>A new <see cref="AcousticImpedance{T}"/> instance.</returns>
-	public static AcousticImpedance<T> FromPascalSecondPerMeter(T value) => Create(value);
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static AcousticImpedance<T> FromPascalSecondPerMeter(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
+/// <summary>
+	/// Subtracts two AcousticImpedance values, returning the absolute difference as a non-negative AcousticImpedance.
+	/// Magnitude subtraction stays a magnitude (per the unified-vector model).
+	/// </summary>
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static AcousticImpedance<T> operator -(AcousticImpedance<T> left, AcousticImpedance<T> right) => Create(T.Abs(left.Quantity - right.Quantity));
 };
 

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/ActivationEnergy.g.cs

@@ -19,12 +19,14 @@ public record ActivationEnergy<T> : PhysicalQuantity<ActivationEnergy<T>, T>, IV
 	public static ActivationEnergy<T> Zero => Create(T.Zero);
 
 	/// <summary>Creates a new ActivationEnergy from a value in JoulePerMole.</summary>
-	public static ActivationEnergy<T> FromJoulePerMole(T value) => Create(value);
+	public static ActivationEnergy<T> FromJoulePerMole(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 /// <summary>Implicit conversion to MolarEnergy.</summary>
 	public static implicit operator MolarEnergy<T>(ActivationEnergy<T> value) => MolarEnergy<T>.Create(value.Value);
 /// <summary>Explicit conversion from MolarEnergy.</summary>
 	public static explicit operator ActivationEnergy<T>(MolarEnergy<T> value) => Create(value.Value);
 /// <summary>Creates a ActivationEnergy from a MolarEnergy value.</summary>
 	public static ActivationEnergy<T> From(MolarEnergy<T> value) => Create(value.Value);
+/// <summary>Subtracts two ActivationEnergy values, returning the absolute difference as a non-negative ActivationEnergy.</summary>
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static ActivationEnergy<T> operator -(ActivationEnergy<T> left, ActivationEnergy<T> right) => Create(T.Abs(left.Quantity - right.Quantity));
 };
 

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/Admittance.g.cs

@@ -19,12 +19,14 @@ public record Admittance<T> : PhysicalQuantity<Admittance<T>, T>, IVector0<Admit
 	public static Admittance<T> Zero => Create(T.Zero);
 
 	/// <summary>Creates a new Admittance from a value in Siemens.</summary>
-	public static Admittance<T> FromSiemens(T value) => Create(value);
+	public static Admittance<T> FromSiemens(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 /// <summary>Implicit conversion to Conductance.</summary>
 	public static implicit operator Conductance<T>(Admittance<T> value) => Conductance<T>.Create(value.Value);
 /// <summary>Explicit conversion from Conductance.</summary>
 	public static explicit operator Admittance<T>(Conductance<T> value) => Create(value.Value);
 /// <summary>Creates a Admittance from a Conductance value.</summary>
 	public static Admittance<T> From(Conductance<T> value) => Create(value.Value);
+/// <summary>Subtracts two Admittance values, returning the absolute difference as a non-negative Admittance.</summary>
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static Admittance<T> operator -(Admittance<T> left, Admittance<T> right) => Create(T.Abs(left.Quantity - right.Quantity));
 };
 

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/Airspeed.g.cs

@@ -19,14 +19,14 @@ public record Airspeed<T> : PhysicalQuantity<Airspeed<T>, T>, IVector0<Airspeed<
 	public static Airspeed<T> Zero => Create(T.Zero);
 
 	/// <summary>Creates a new Airspeed from a value in MetersPerSecond.</summary>
-	public static Airspeed<T> FromMetersPerSecond(T value) => Create(value);
+	public static Airspeed<T> FromMetersPerSecond(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 /// <summary>Implicit conversion to Speed.</summary>
 	public static implicit operator Speed<T>(Airspeed<T> value) => Speed<T>.Create(value.Value);
 /// <summary>Explicit conversion from Speed.</summary>
 	public static explicit operator Airspeed<T>(Speed<T> value) => Create(value.Value);
 /// <summary>Creates a Airspeed from a Speed value.</summary>
 	public static Airspeed<T> From(Speed<T> value) => Create(value.Value);
-/// <summary>Subtracts two Airspeed values, returning a signed Velocity1D result.</summary>
-	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static Velocity1D<T> operator -(Airspeed<T> left, Airspeed<T> right) => Velocity1D<T>.Create(left.Quantity - right.Quantity);
+/// <summary>Subtracts two Airspeed values, returning the absolute difference as a non-negative Airspeed.</summary>
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static Airspeed<T> operator -(Airspeed<T> left, Airspeed<T> right) => Create(T.Abs(left.Quantity - right.Quantity));
 };
 

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/Altitude.g.cs

@@ -19,14 +19,14 @@ public record Altitude<T> : PhysicalQuantity<Altitude<T>, T>, IVector0<Altitude<
 	public static Altitude<T> Zero => Create(T.Zero);
 
 	/// <summary>Creates a new Altitude from a value in Meter.</summary>
-	public static Altitude<T> FromMeter(T value) => Create(value);
+	public static Altitude<T> FromMeter(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 /// <summary>Implicit conversion to Length.</summary>
 	public static implicit operator Length<T>(Altitude<T> value) => Length<T>.Create(value.Value);
 /// <summary>Explicit conversion from Length.</summary>
 	public static explicit operator Altitude<T>(Length<T> value) => Create(value.Value);
 /// <summary>Creates a Altitude from a Length value.</summary>
 	public static Altitude<T> From(Length<T> value) => Create(value.Value);
-/// <summary>Subtracts two Altitude values, returning a signed Displacement1D result.</summary>
-	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static Displacement1D<T> operator -(Altitude<T> left, Altitude<T> right) => Displacement1D<T>.Create(left.Quantity - right.Quantity);
+/// <summary>Subtracts two Altitude values, returning the absolute difference as a non-negative Altitude.</summary>
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static Altitude<T> operator -(Altitude<T> left, Altitude<T> right) => Create(T.Abs(left.Quantity - right.Quantity));
 };
 

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/AmountOfSubstance.g.cs

@@ -22,7 +22,13 @@ public record AmountOfSubstance<T> : PhysicalQuantity<AmountOfSubstance<T>, T>,
 	/// </summary>
 	/// <param name="value">The value in Mole.</param>
 	/// <returns>A new <see cref="AmountOfSubstance{T}"/> instance.</returns>
-	public static AmountOfSubstance<T> FromMole(T value) => Create(value);
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static AmountOfSubstance<T> FromMole(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
+/// <summary>
+	/// Subtracts two AmountOfSubstance values, returning the absolute difference as a non-negative AmountOfSubstance.
+	/// Magnitude subtraction stays a magnitude (per the unified-vector model).
+	/// </summary>
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static AmountOfSubstance<T> operator -(AmountOfSubstance<T> left, AmountOfSubstance<T> right) => Create(T.Abs(left.Quantity - right.Quantity));
 /// <summary>
 	/// Divides AmountOfSubstance by Volume to produce Concentration.
 	/// </summary>

Semantics.Quantities/Generated/Semantics.SourceGenerators/Semantics.SourceGenerators.QuantitiesGenerator/Angle.g.cs

@@ -22,11 +22,13 @@ public record Angle<T> : PhysicalQuantity<Angle<T>, T>, IVector0<Angle<T>, T>
 	/// </summary>
 	/// <param name="value">The value in Radian.</param>
 	/// <returns>A new <see cref="Angle{T}"/> instance.</returns>
-	public static Angle<T> FromRadian(T value) => Create(value);
+	/// <exception cref="System.ArgumentException">Thrown when the resulting magnitude would be negative.</exception>
+	public static Angle<T> FromRadian(T value) => Create(Vector0Guards.EnsureNonNegative(value, nameof(value)));
 /// <summary>
-	/// Subtracts two Angle values, returning a signed SignedAngle result.
+	/// Subtracts two Angle values, returning the absolute difference as a non-negative Angle.
+	/// Magnitude subtraction stays a magnitude (per the unified-vector model).
 	/// </summary>
-	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static SignedAngle<T> operator -(Angle<T> left, Angle<T> right) => SignedAngle<T>.Create(left.Quantity - right.Quantity);
+	[System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "CA2225:Operator overloads have named alternates", Justification = "Physics quantity operator")] public static Angle<T> operator -(Angle<T> left, Angle<T> right) => Create(T.Abs(left.Quantity - right.Quantity));
 /// <summary>
 	/// Divides Angle by Duration to produce AngularSpeed.
 	/// </summary>