Add CodeQL code scanning

[basmussen]

Summary

• Add CodeQL analysis workflow for automated security scanning
• Enable code scanning for Java/Kotlin code

Features

• Runs on push to develop/master branches
• Runs on pull requests to develop/master branches
• Weekly scheduled scan (Mondays at 5:30 AM)
• Uses security-and-quality query suite for comprehensive analysis

Benefits

• Automated detection of security vulnerabilities
• Code quality analysis
• Integration with GitHub Security tab
• Prevents security issues from reaching production

Test plan

• Verify workflow runs successfully on merge
• Check that CodeQL results appear in Security tab
• Confirm no false positives in initial scan

[github-advanced-security]

This pull request sets up GitHub code scanning for this repository. Once the scans have completed and the checks have passed, the analysis results for this pull request branch will appear on this overview. Once you merge this pull request, the 'Security' tab will show more code scanning analysis results (for example, for the default branch). Depending on your configuration and choice of analysis tool, future pull requests will be annotated with code scanning analysis results. For more information about GitHub code scanning, check out the documentation.