FixedMathSharp-Unity v5.0.0

This release updates both Unity Package Manager variants to FixedMathSharp 5.0.0 and aligns the Unity adapters with the core v5 API and coordinate semantics.

Breaking Changes

• Updated the embedded FixedMathSharp binaries and XML docs to v5.0.0.
• Unity adapter code now follows the core v5 naming model, including PascalCase vector, quaternion, bounds, and matrix members such as X/Y/Z, W, and M11-style matrix fields.
• Matrix and transform conversions now use explicit semantic mapping between FixedMathSharp row-vector matrices and Unity transforms, including translation mapping between FixedMathSharp M41/M42/M43 and Unity m03/m13/m23.
• Removed the old standalone Matrix4x4.Extensions.cs and Transform.Extensions.cs organization; those helpers now live with the fixed-type extension surfaces.

Highlights

• Added clearer Unity/FixedMathSharp coordinate semantics: +X right, +Y up, and +Z forward are preserved across vector, quaternion, matrix, and transform conversions.
• Added explicit XY and XZ vector projection helpers for 2D/3D Unity interop.
• Added Unity-to-fixed transform round-trip helpers, including local/world Transform -> Fixed4x4 -> Transform workflows.
• Hardened inspector drawers for FixedMathSharp v5 serialization, including fixed number, vector, matrix, quaternion, and angle/rotation drawers.
• Renamed and refreshed bounds interop around FixedBoundBox and FixedBoundArea.
• Added EditMode tests covering vector projections, coordinate conventions, matrix translation semantics, and transform round trips.
• Added package version sync tooling and refreshed developer guidance for maintaining the base package source and generated UPM variants.