3d jan/beamlattice namespace fix

[3dJan]

• Writer now detects ball usage up‑front and (when needed) declares xmlns:b2 and emits b2:balls, b2:ball, and b2:ballref instead of the previous (non‑spec) <b:ball*>.
• Added new constants for the balls namespace/prefix and integrated them into required extension handling.
• Reader extended to:
• Accept the balls namespace for / elements.
• Parse namespaced b2:ballmode and b2:ballradius attributes.
• Treat the balls namespace as a supported required extension (removes prior warning).
• Remain backward compatible with legacy files using <b:balls> / <b:ball>.
• New test 3MF asset plus test validating: no warnings, ball mode = All, default radius = 3.0, total implicit balls = vertex count (8).
• Added a namespace compliance test ensuring serialization uses b2 and never falls back to legacy b:ball forms.

[Copilot]

Pull Request Overview

This PR implements proper namespace support for beam lattice balls in the 3MF specification by introducing a dedicated balls namespace (b2:) to replace the non-compliant legacy b:ball* elements. The changes ensure spec compliance while maintaining backward compatibility.

Key changes:

• Adds detection logic to determine when balls extension is needed and declares appropriate namespace
• Updates writer to emit proper b2:balls, b2:ball, and b2:ballref elements instead of legacy forms
• Extends reader to accept both new balls namespace and legacy b:ball* for backward compatibility

Reviewed Changes

Copilot reviewed 19 out of 21 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
Source/Model/Writer/v100/NMR_ModelWriterNode100_Model.cpp	Adds ball usage detection and namespace declaration logic
Source/Model/Writer/v100/NMR_ModelWriterNode100_Mesh.cpp	Updates to use balls namespace prefix for ball elements
Source/Model/Reader/BeamLattice1702/NMR_ModelReaderNode_BeamLattice1702_BeamLattice.cpp	Adds support for namespaced ball attributes
Include/Model/Classes/NMR_ModelConstants.h	Defines new balls namespace constants
Tests/CPP_Bindings/Source/BeamLattice.cpp	Adds test for balls extension compliance

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[3dJan]

just noticed that in CI build https://github.com/3dJan/lib3mf/actions/runs/17714380031/job/50337632342 the
integration-test-last-commit-and-last-release failed

[3dJan]

There seems to be indeed a regression, two negative tests pass now:
=== Regressions (commit vs release) - MUSTFAIL now passing:
/home/runner/work/lib3mf/lib3mf/test_suites/suite7_beam/negative_test_cases/N_BXX_2506_01.3mf
/home/runner/work/lib3mf/lib3mf/test_suites/suite7_beam/negative_test_cases/N_BXX_2506_07.3mf

Btw. I now also extended the integration tests to list the test cases with regressions.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 59.08%. Comparing base (fce4988) to head (400edfe).
⚠️ Report is 19 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop     #433   +/-   ##
========================================
  Coverage    59.08%   59.08%           
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  Files           64       64           
  Lines        23589    23589           
========================================
  Hits         13937    13937           
  Misses        9652     9652           

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[Copilot]

Pull Request Overview

Copilot reviewed 24 out of 26 changed files in this pull request and generated no new comments.

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[gangatp]

looks good

[vijaiaeroastro]

Looks good, Jan. Thanks for the changes in integration tests too.