2.3.0 release review notes

PR #58 added the stiff ODE solver and merged into main as b0f8d71. The change preserves the published 2.2.0 API snapshot and adds a versioned 2.3.0 API reference.

Linux CI exposed a nonlinear Newton branch failure on the Robertson reference problem. The stage solve now refreshes its Jacobian and backtracks until the scaled implicit residual decreases. Linux and Windows CI both pass on the merged feature commit.

PR #59 passed Linux and Windows CI on its release commit. The full checksummed clean-archive qualification also passed on both platforms; Linux ran with outbound connections blocked, and Windows built the Lazarus package for Win32 and Win64. Run and artifact details are in the qualification record.