🎉 Enhance public APIs and add new features

[munechika-koyo]

Key changes include:

• Reveal load2d and load3d modules as public APIs.

• Enhance base_mesh and unstruct_2d_extend_mesh with type hints and utility functions.

• Add line of sight handling functions and update _bolo_data for cylindrical coordinates.

• Introduce UnstructGrid3D class and improve plotting styles in GGDGrid and UnstructGrid2D.

• Update CSS MathJax configuration for Myst-parser daller representation

• Remove unnecessary license-files entry from pyproject.toml.

• Add environment configuration for cherab-imas-nblink.

• Include test scripts for line of sight handling.

• Update axis labels in UnstructGrid2D for better readability.

[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 158 lines in your changes missing coverage. Please review.
✅ Project coverage is 62.89%. Comparing base (be1b108) to head (b4d4907).
⚠️ Report is 22 commits behind head on master.

Files with missing lines	Patch %	Lines
src/cherab/imas/ggd/unstruct_3d_mesh.py	28.12%	92 Missing ⚠️
src/cherab/imas/ggd/unstruct_2d_extend_mesh.py	12.00%	44 Missing ⚠️
src/cherab/imas/ggd/unstruct_2d_mesh.py	51.21%	18 Missing and 2 partials ⚠️
src/cherab/imas/ids/wall/__init__.py	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #31      +/-   ##
==========================================
- Coverage   63.90%   62.89%   -1.01%     
==========================================
  Files          46       48       +2     
  Lines        2820     3043     +223     
  Branches      468      491      +23     
==========================================
+ Hits         1802     1914     +112     
- Misses        813      923     +110     
- Partials      205      206       +1     

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[Copilot]

Pull request overview

This pull request expands CHERAB-IMAS public APIs and adds new grid/observer utilities, with accompanying documentation/config updates and new tests to validate bolometer line-of-sight (LOS) handling.

Changes:

• Expose additional public entry points (e.g., wall.load2d/load3d, bolometer LOS helpers) and add LOS extraction/interpolation utilities.
• Introduce UnstructGrid3D and refine GGD mesh APIs (type hints, subset selection helpers, plotting style controls, label formatting).
• Update built-in bolometer dataset cylindrical-coordinate handling + LOS fields, and update docs/CSS plus a new .nblink environment definition.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
tests/observer/test_bolometer.py	Adds tests for LOS extraction and interpolated LOS spacing.
src/cherab/imas/ids/wall/init.py	Exposes load2d/load3d modules as public API.
src/cherab/imas/ids/bolometer/_los.py	Adds LOS extraction and interpolation utilities for bolometer IDS.
src/cherab/imas/ids/bolometer/init.py	Exposes get_los() / get_los_interp() as public API.
src/cherab/imas/ggd/unstruct_3d_mesh.py	Adds new UnstructGrid3D implementation.
src/cherab/imas/ggd/unstruct_2d_mesh.py	Tightens typing around cell indices and subset selection; improves plotting styles/labels.
src/cherab/imas/ggd/unstruct_2d_extend_mesh.py	Adds typing/helpers, plotting improvements, and changes subset behavior for extended grids.
src/cherab/imas/ggd/base_mesh.py	Introduces CellSelection + as_index_array() and updates abstract method signatures.
src/cherab/imas/ggd/init.py	Exposes base_mesh and newly added UnstructGrid3D.
src/cherab/imas/datasets/_builtin.py	Updates bolometer mock data to use cylindrical helpers and populate LOS fields.
pyproject.toml	Removes license-files entry.
docs/source/conf.py	Refactors repo/link settings, adjusts Sphinx theme options, and updates nbsphinx_prolog templating.
docs/source/_static/custom.css	Adds MathJax display/overflow styling (and commented dark-theme tweaks).
.nblink/environment.yml	Adds a conda environment definition for notebook linking/build workflows.

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