Fix scalar process noise in random matrix tracker

[FlorianPfaff]

Summary

• normalize RandomMatrixTracker.predict() process noise through the active backend before inspecting its shape
• restore support for Python scalar process-noise inputs by expanding them to isotropic covariance matrices
• add a focused regression test for scalar Cw

Rationale

RandomMatrixTracker.predict() already intended to accept scalar process noise via the Cw.shape in ((), (1,)) branch. However, unlike the factorized GIW random-matrix tracker, it inspected Cw.shape before coercing Cw into a backend array. Passing a natural Python scalar such as 0.05 therefore raised AttributeError instead of producing 0.05 * eye(state_dim).

Validation

• connector compare confirms this branch is ahead of main by two commits and behind by zero
• changes are limited to src/pyrecest/filters/random_matrix_tracker.py and tests/filters/test_random_matrix_tracker.py
• direct local pytest execution was not possible in this environment; PR CI should run the focused and full test matrix

[github-actions]

✅⚠️MegaLinter analysis: Success with warnings

Descriptor	Linter	Files	Fixed	Errors	Warnings	Elapsed time
✅ COPYPASTE	jscpd	yes		no	no	39.21s
✅ JSON	prettier	7	0	0	0	1.01s
✅ JSON	v8r	7		0	0	4.3s
⚠️ MARKDOWN	markdownlint	66	0	1	0	1.78s
✅ MARKDOWN	markdown-table-formatter	66	0	0	0	0.75s
✅ PYTHON	black	755	8	0	0	33.79s
✅ PYTHON	isort	755	8	0	0	2.21s
✅ REPOSITORY	checkov	yes		no	no	41.77s
✅ REPOSITORY	gitleaks	yes		no	no	16.86s
✅ REPOSITORY	git_diff	yes		no	no	0.04s
✅ REPOSITORY	secretlint	yes		no	no	22.0s
✅ REPOSITORY	syft	yes		no	no	4.56s
✅ REPOSITORY	trivy-sbom	yes		no	no	5.25s
✅ REPOSITORY	trufflehog	yes		no	no	21.34s
✅ YAML	prettier	10	0	0	0	0.61s
✅ YAML	v8r	10		0	0	11.1s
✅ YAML	yamllint	10		0	0	0.47s

Detailed Issues

⚠️ MARKDOWN / markdownlint - 1 error

.github/pull_request_template.md:1 error MD041/first-line-heading/first-line-h1 First line in a file should be a top-level heading [Context: "## Summary"]

Notices

📣 MegaLinter 9.5.0 is out! Discover the new features and security recommendations in the release announcement. (Skip this info by defining SECURITY_SUGGESTIONS: false)

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@9.5.0 --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_GITLEAKS,REPOSITORY_SECRETLINT,REPOSITORY_SYFT,REPOSITORY_TRIVY_SBOM,REPOSITORY_TRUFFLEHOG,YAML_PRETTIER,YAML_YAMLLINT,YAML_V8R

Show us your support by starring ⭐ the repository