feat/fix: migrate linting to Warnings NG and restore coverage overview

[Gearlux]

Summary

• Key Features:
  • Migrated linting and static analysis (Black, Isort, Flake8, Mypy) to the Warnings Next Generation plugin for separate trend graphs.
  • Restored the Jenkins Coverage Overview by consolidating code coverage into a single recordCoverage call with the default ID.
  • Robust Checkstyle XML generation for Black and Isort formatting results.
  • Consolidated documentation (REQUIREMENTS.md into README.md) and updated installation instructions.
• Detailed Changes:
  • 68fd5a4, ad0e764, b5b5df7: Jenkinsfile reporting overhaul and syntax fixes.
  • d4d78f2, 3a51b05: Documentation consolidation and project-level fixes.
  • 42e9c49: Node 24 support improvements.
• Quality & Coverage: Verified locally from root; all tests passing with 94% coverage.