expose the projectors and shared geometry to Python

[zeerekahmad]

PR: expose the projectors and shared geometry to Python

• branch: zeerekahmad/kinematics-python-bindings
• base: zeerekahmad/kinematics-dual-build
• commit: 1c96c08

Description

Brings the new C++ API to Python.

• Binds Pose2D, Point2D, AxleReference, rectangle_footprint and transform_footprint, plus all three
  projectors and their projected-state structs. Footprint is std::vector<Point2D>, which pybind11/stl.h
  renders as a plain list of Point2D; the package aliases it so annotations can name the concept.
• Removes Twist2D, normalize_angle and transform_pose from the Python package. They were leftovers
  from when Pose2D was a Python shim, and are superseded by the bound C++ Pose2D and normalizeAngle.
• ament_add_pytest_test now names test_python_bindings.py explicitly rather than the test directory, so
  adding a pytest suite doesn't silently join this target, and runs it from the source directory.

Migration Guide

Breaking for Python callers of the removed shims:

1. Replace from polymath_kinematics import Twist2D with the bound C++ types — construct the body command
   directly from the model/projector API (linear_velocity_m_s, angular_velocity_rad_s).
2. Replace normalize_angle(theta) with the bound normalize_angle from the C++ normalizeAngle.
3. Replace transform_pose(...) with Pose2D and transform_footprint(...).

No C++ callers are affected.

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 💬}