refactor: simplify clenshaw summations

[tsutterley]

No description provided.

[Copilot]

Pull request overview

This PR refactors how the complex longitude phase terms (exp(1j*m*phi)) are generated for Clenshaw-style spherical harmonic summations, and updates CI path filters so Python tests run when additional top-level packages change.

Changes:

• Refactors exp(1j*m*phi) construction in both sea_level_equation and clenshaw_summation to a fully-vectorized np.exp(...) computation.
• Renames the _clenshaw return variable from s_m-style naming to cs_m for consistency with callers.
• Expands the .github/workflows/python-request.yml pull_request path filters to include additional package directories.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
gravity_toolkit/sea_level_equation.py	Precomputes m_phi via vectorized exponentials outside the iterative solver loop.
gravity_toolkit/clenshaw_summation.py	Vectorizes m_phi generation and renames _clenshaw internal/return variable to cs_m.
.github/workflows/python-request.yml	Triggers the Python workflow on changes in more top-level source directories.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[tsutterley]

@copilot review the updated gravity_toolkit/sea_level_equation.py and gravity_toolkit/clenshaw_summation.py programs

[Copilot]

@copilot review the updated gravity_toolkit/sea_level_equation.py and gravity_toolkit/clenshaw_summation.py programs

Reviewed the current committed state at d052157. The backward phase recurrence in both files is numerically consistent, the focused test/test_sea_level.py check passes, and CodeQL is clean. I only found one minor follow-up in gravity_toolkit/sea_level_equation.py: the np.multiply(cs_m[jj], m_phi_current[ii]).real expression could be simplified to direct multiplication for consistency with clenshaw_summation.py, but I did not make code changes.