Add missing files to the documentation

[dkuegler]

The documentation had a couple of files missing, specifically I became aware of this in #790, when I wanted to point to a function in brainvolstats. This PR adds missing python files to the sphinx documentation, fixes their docstrings so the documentation builds and finally adds missing or incomplete docstrings in brainvolstats.

[Copilot]

Pull request overview

This pull request addresses missing documentation for several Python modules in FastSurfer, improving the Sphinx documentation build and adding comprehensive docstrings to the brainvolstats module. The changes were motivated by issue #790, which highlighted the need to reference functions in brainvolstats from the documentation.

Changes:

• Added missing module references to Sphinx documentation configuration files for recon_surf, HypVINN.utils, FastSurferCNN.utils, FastSurferCNN, FastSurferCNN.models, CorpusCallosum.shape, and CorpusCallosum.data
• Fixed documentation filename references (corrected CerebNet.dataloader to CerebNet.data_loader)
• Added comprehensive docstrings to brainvolstats.py, including detailed parameter descriptions, return types, and cross-references
• Improved docstrings across multiple modules with better type annotations and formatting consistency
• Renamed with_header parameter to return_header in readITKimage function and updated all call sites
• Fixed import statement in generate_fsaverage_centroids.py to use proper module path

Reviewed changes

Copilot reviewed 19 out of 20 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
doc/api/recon_surf.rst	Added missing modules: image_io, long_compat_segmentHA, spherically_project
doc/api/index.rst	Fixed typo: CerebNet.dataloader → CerebNet.data_loader
doc/api/HypVINN.utils.rst	Added missing utility modules to documentation
doc/api/FastSurferCNN.utils.rst	Added brainvolstats and dataclasses to utils documentation
doc/api/FastSurferCNN.rst	Added missing top-level modules (mri_brainvol_stats, mri_segstats, run_model, train)
doc/api/FastSurferCNN.models.rst	Added optimizer module
doc/api/CorpusCallosum.shape.rst	Reordered and added missing shape module entries
doc/api/CorpusCallosum.data.rst	Added generate_fsaverage_centroids module
doc/api/CerebNet.data_loader.rst	Fixed header from dataloader to data_loader
recon_surf/spherically_project.py	Improved docstring formatting and consistency
recon_surf/image_io.py	Enhanced type hints, renamed parameter, improved docstrings
recon_surf/align_seg.py	Updated function calls to use renamed parameter
recon_surf/N4_bias_correct.py	Updated function calls to use renamed parameter
HypVINN/utils/visualization_utils.py	Added update_docstring decorator for dynamic default documentation
HypVINN/utils/load_config.py	Minor docstring formatting fix
HypVINN/utils/img_processing_utils.py	Minor docstring formatting improvement
FastSurferCNN/utils/dataclasses.py	Improved docstring cross-references and formatting
FastSurferCNN/utils/brainvolstats.py	Extensive docstring additions for all classes and methods
FastSurferCNN/train.py	Clarified return value documentation
CorpusCallosum/data/generate_fsaverage_centroids.py	Fixed import statement to use full module path

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[m-reuter]

in my actions I moved to python 3.13, also in build matrix I now do 3.10 , 3.11, 3.12 and 3.13 (dropping 3.9). And remove
architecture: 'x64' as that is too restrictive and collides with Mac architectures .

[dkuegler]

Don't really need to test different versions to build the documentation... But I think we might want to move to UV in actions as well, I'll let copilot work on that tomorrow...