Add web linters to Makefile and lint-web.yml GitHub Actions

[crivetimihai]

Add lint-web to CI/CD and add additional linters to Makefile (jshint jscpd markuplint) - closes #390

Add web linting to our CI/CD pipeline to ensure frontend code quality and security. This includes creating a new GitHub workflow (lint-web.yml) that runs HTML, CSS, and JavaScript linters in parallel jobs, similar to our existing Python lint workflow.

Tasks:

• Create .github/workflows/lint-web.yml with matrix jobs for:
  • htmlhint (HTML validation)
  • stylelint (CSS linting)
  • eslint (JavaScript linting)
  • retire (vulnerability scanning)
  • npm audit (dependency security)
  • jshint (Additional JS analysis with ES11 support)
  • jscpd (Copy/paste detection across JS/HTML/CSS)
  • markuplint (Modern HTML validation)
  • nodejsscan (JS security analysis - separate Python job)
• Add new linter targets to Makefile:
  • jshint - Additional JS analysis with ES11 support
  • jscpd - Copy/paste detection across JS/HTML/CSS
  • markuplint - Modern HTML validation
• Update install-web-linters target to include new tools
• Create .jshintrc config file for consistent JS standards

Benefits:

• Automated frontend code quality checks on every PR
• Early detection of security vulnerabilities
• Consistent code standards across HTML/CSS/JS
• Reduced technical debt through duplicate code detection
• Comprehensive coverage with 9 different linting tools