Fix subclass-preserving distribution conversion factories

[FlorianPfaff]

What changed

• Convert LinearDiracDistribution.from_distribution, CircularDiracDistribution.from_distribution, SE2DiracDistribution.from_distribution, and SE3DiracDistribution.from_distribution from static factories to class factories.
• Convert CircularGridDistribution.from_distribution and CircularGridDistribution.from_function to class factories as well.
• Construct cls(...) instead of hard-coding the base distribution type.
• Route particle-count validation through cls for the Euclidean/SE factories.
• Add regression coverage through the public convert_distribution gateway for subclasses of all five affected target families.

Root cause

convert_distribution(source, TargetSubclass, ...) resolves TargetSubclass.from_distribution. Several inherited factories were static methods that explicitly constructed the base class, so the conversion silently returned the wrong concrete type even though the requested target was the subclass. CircularGridDistribution.from_distribution also delegated to a static from_function that hard-coded CircularGridDistribution, so simply inheriting the factory could not preserve an extension class.

Impact

Subclass-based extensions of these core Dirac and circular-grid representations now retain their requested concrete type during representation conversion. Ordinary base-class conversions keep the same behavior and signatures.

Validation

• tests/distributions/test_dirac_factory_subclass_preservation.py now contains five gateway regressions, including circular-grid conversion from a von Mises source.
• The branch is based on current main (fc15bed910b324cd0619a2f2b71abc887bc09747).
• Full backend/test-matrix validation is delegated to GitHub Actions because the current execution environment cannot clone GitHub dependencies locally.

[github-actions]

✅MegaLinter analysis: Success

Descriptor	Linter	Files	Fixed	Errors	Max errors	Warnings	Elapsed time
✅ COPYPASTE	jscpd	yes		no		no	8.2s
✅ JSON	prettier	7	0	0		0	0.8s
✅ JSON	v8r	7		0		0	3.97s
✅ MARKDOWN	markdownlint	68	0	0		0	1.9s
✅ MARKDOWN	markdown-table-formatter	68	0	0		0	0.45s
✅ PYTHON	black	1984	12	0		0	58.06s
✅ PYTHON	isort	1984	22	0		0	2.84s
✅ REPOSITORY	betterleaks	yes		no		no	1.06s
✅ REPOSITORY	checkov	yes		no		no	35.82s
✅ REPOSITORY	git_diff	yes		no		no	0.13s
✅ REPOSITORY	secretlint	yes		no		no	99.54s
✅ REPOSITORY	syft	yes		no		no	2.96s
✅ REPOSITORY	trivy-sbom	yes		no		no	2.07s
✅ YAML	prettier	11	0	0		0	0.78s
✅ YAML	v8r	11		0		0	14.21s
✅ YAML	yamllint	11		0		0	0.94s

Notices

⚠️ Your configuration references items that have been removed from MegaLinter and are ignored: MAKEFILE_CHECKMAKE. See Removed linters to find their replacements.

See detailed reports in MegaLinter artifacts

Your project could benefit from a custom flavor, which would allow you to run only the linters you need, and thus improve runtime performances. (Skip this info by defining FLAVOR_SUGGESTIONS: false)

• Documentation: Custom Flavors
• Command: npx mega-linter-runner@10.0.0 --custom-flavor-setup --custom-flavor-linters PYTHON_BLACK,PYTHON_ISORT,COPYPASTE_JSCPD,JSON_V8R,JSON_PRETTIER,MARKDOWN_MARKDOWNLINT,MARKDOWN_MARKDOWN_TABLE_FORMATTER,REPOSITORY_CHECKOV,REPOSITORY_GIT_DIFF,REPOSITORY_BETTERLEAKS,REPOSITORY_SECRETLINT,REPOSITORY_SYFT,REPOSITORY_TRIVY_SBOM,YAML_PRETTIER,YAML_YAMLLINT,YAML_V8R

Show us your support by starring ⭐ the repository