add forward projectors for all three kinematic models

[zeerekahmad]

PR: add forward projectors for all three kinematic models

• branch: zeerekahmad/kinematics-projectors
• base: zeerekahmad/lint-precommit-cleanup
• commit: 958c561

Description

Introduces forward projection for all three kinematic models: simulation that ramps the actuator command
toward a target under a rate or acceleration limit, clamps it to the configured range, and integrates pose
with Euler. Each projector exposes step() for one time step and project() for a full horizon, returning a
timestamped state sequence whose element 0 is the initial state.

• BicycleProjector, ArticulatedProjector and DifferentialDriveProjector, with Catch2 coverage for each.
• Shared 2D geometry in pose2d.hpp: Pose2D, Point2D, Footprint (a CCW, unclosed polygon of any vertex
  count), normalizeAngle, transformFootprint, offsetAlongHeading and rectangleFootprint. Projectors
  optionally carry a body-frame polygon and emit it transformed into the world frame per sample, so the
  kinematic models stay dimension-free.
• AxleReference selects which axle the bicycle and articulated projectors measure poses and footprints from.
  Motion is still integrated where each model is naturally defined (the rear axle) and converted on input and
  output, so no integration accuracy is traded for the choice.
• ArticulatedModel gains an explicit articulation turning velocity (gamma-dot) on
  bodyVelocityToVehicleState and articulationToAxleVelocities, replacing the hardcoded zero constant. The
  two-argument forms remain as overloads assuming steady articulation, so existing callers are unaffected.
• Those overloads make the existing bindings ambiguous: kinematics_pybind.cpp passed bare member-function
  pointers, which no longer resolve once a second overload exists. Both bindings move to py::overload_cast
  on the three-argument form and expose gamma-dot as a keyword argument defaulting to 0.0, so Python callers
  keep the two-argument call and gain the rate.
• catch_discover_tests switches to DISCOVERY_MODE PRE_TEST. The default POST_BUILD runs each test binary
  during the build, where an older installed libpolymath_kinematics.so wins on LD_LIBRARY_PATH.

Migration Guide

None required — the additions are source and binary compatible. The two-argument C++ overloads and the
two-argument Python calls behave exactly as before (steady articulation, gamma-dot = 0).

Related issues

Completeness checklist

• Is there test coverage? If it was a bugfix, is there a regression test?
• Is user-facing API/behavior documented?
• Is core documentation updated?
• Are all checks green?
• Assign reviewers to the PR and post in #code_reviews

---

_{Stack created with GitHub Stacks CLI • Give Feedback 💬}