Format

[zhengp0]

Summary

A formatting and documentation cleanup pass on top of the numpy 2
compatibility fixes. No runtime behavior changes — this is purely
style, docstrings, and lint hygiene.

• Apply ruff format across the package, tests, and setup.py
  (quote style, spacing, line wrapping).
• Convert all docstrings from Google style (Args:/Returns:) to
  NumPy style (Parameters/Returns with underlines).
• Tidy imports and the public API surface.

What changed

• Docstrings (src/xspline/core.py, src/xspline/utils.py) —
  converted every function/method to NumPy style. Argument types are
  dropped from the docstrings (to be carried by type hints later);
  return types are kept. XSpline / NDXSpline constructor
  parameters moved into the class docstring with an Attributes
  section. Dropped the r""" prefixes (no docstring uses backslashes)
  and removed the module-level docstrings/header comments.
• Imports & public API (src/xspline/__init__.py) — replaced
  from .core import * with explicit imports and an explicit
  __all__ listing the four bspline_* functions and the XSpline /
  NDXSpline classes.
• Formatting (setup.py, src/xspline/__about__.py, all of
  tests/) — ruff format reflow and import-order fixes; removed an
  unused variable in tests/test_xspline.py.

[codacy-production]

Not up to standards ⛔

_{NEW Get contextual insights on your PRs based on Codacy's metrics, along with PR and Jira context, without leaving GitHub. Enable AI reviewer
TIP This summary will be updated as you push new changes.}