Fix Plane intersection Python defaults

[timothyanderson096-ocdealcheck]

🦟 Bug fix

Refs #808.

Summary

Plane.intersection() currently accepts calls without a point or gradient even though the C++ API requires both arguments. This change removes those two Python binding defaults, retains the optional tolerance, and adds regression coverage for zero- and one-argument calls.

Before this change, plane.intersection() is accepted. After this change, missing point or gradient arguments raise TypeError, while the two-argument call succeeds and _tolerance remains optional.

Backport Policy

• I am not sure

Testing

• compiled the affected pybind11 binding from current main with a focused harness
• verified the baseline accepts Plane.intersection() with zero arguments
• verified the patched binding raises TypeError for missing point / gradient
• verified the two-argument call succeeds and tolerance remains optional
• git diff --check

The full CMake suite was not run locally because the test container does not include the project's CMake dependencies.

Checklist

• Signed all commits for DCO
• Added a screen capture or video to the PR description that demonstrates the fix (as needed)
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Considered updating Python bindings
• codecheck passed
• All tests passed
• Updated Bazel files (no files added)
• Reviewed another open pull request
• GenAI was used and the commit includes an Assisted-by trailer

Some portions of this pull request were generated using OpenAI Codex (GPT-5.6).

Assisted-by: OpenAI Codex (GPT-5.6)