Fix acceleration limits and link velocity guard

[KohmeiK]

Summary

This is a three-line change in one solver file:

• finite analytic acceleration solutions near toggle points are no longer rejected solely for exceeding heuristic magnitude limits
• link angular velocity is checked against the angular-velocity limit instead of the dimensionally incompatible joint linear-velocity limit

The kinematic equations, matrix solve, nonfinite-result check, all-zero-result behavior, public API, and every other source file remain unchanged.

Verification

• Release library build passes
• the existing PMKS_Verification oracle runs all five mechanisms successfully
• all five MATLAB-PMKS comparisons pass every aligned row at the existing tolerances