refactor(c++): 🎨 implementation into either source or inline files

[robertodr]

Summary

🤖 AI text below 🤖

This pull request primarily refactors and reorganizes the implementation of graph encoding and cross-rank storage logic in the monoprop library. The main changes involve moving inline function implementations from headers to a new .cpp file, improving encapsulation, and cleaning up header dependencies. Additionally, a new utility function is added for parameter validation.

Refactoring and Implementation Reorganization

• Moved inline implementations from MPGraphEncodingStorage.h and MPGraphEncodingTypes.h into a new source file MPGraphEncoding.cpp, replacing inline functions with declarations in the headers. This improves build times and encapsulation of implementation details. [1] [2] [3] [4] [5] [6] [7]
• Updated CMake configuration to compile the new MPGraphEncoding.cpp file as part of the build.

API and Dependency Cleanups

• Removed unnecessary includes and unused code from headers, reducing header bloat and unnecessary dependencies. [1] [2] [3] [4]
• Changed the inclusion of inline implementation files in MonomialPropagator.h to a single .inl file, further reducing header complexity.

New and Improved Utilities

• Added a new function expected_num_params to Validation.cpp and exposed it in Validation.h, providing a utility to determine the expected number of parameters from a mapping vector. [1] [2]
• Removed unused static utility functions from MonomialPropagator that are now provided elsewhere.

These changes improve code organization, maintainability, and build performance by isolating implementation details and reducing header dependencies.

Checklist

• Tests added or updated to cover the changes
• Documentation updated (docstrings, docs/, CONTRIBUTING.md) if needed
• CHANGELOG / release notes updated if applicable

AI/LLM disclosure

• I did not use LLM tooling, or used it only privately for ideation
• I used the following tool to help write this PR description:
• I used the following tool to generate or modify code: GitHub Copilot, Claude Sonnet 4.6 and Claude Opus 4.8

Important

By opening this PR I confirm that I have read CONTRIBUTING.md and I agree to the terms of the Contributor License Agreement.

Warning

If you're contributing on behalf of your employer, contact cla@algorithmiq.fi to arrange a Corporate CLA.

[github-actions]

Docs preview: https://pr-203.monoprop-docs.pages.dev

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.31%. Comparing base (a20e30f) to head (6bde741).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@                   Coverage Diff                    @@
##           chore-cibuildwheel-conf     #203   +/-   ##
========================================================
  Coverage                    95.31%   95.31%           
========================================================
  Files                           14       14           
  Lines                          704      704           
  Branches                        88       88           
========================================================
  Hits                           671      671           
  Misses                          20       20           
  Partials                        13       13           

Flag	Coverage Δ
cpp	95.31% <ø> (ø)

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[sonarqubecloud]

Quality Gate passed

Issues
9 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud