6 tests pass: zero-force, constant-force, SHO period, analytical precision, interface contract, and large-dt adaptation. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
6 tests pass: zero-force, constant-force, SHO period, analytical precision, interface contract, and large-dt adaptation. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>