feat: implement comprehensive CI/CD workflow suite with automation

[alxkm]

• Add 6 GitHub Actions workflows for complete project automation
• Implement dependency update workflow with OWASP security scanning
• Add performance benchmarking with virtual threads analysis
• Create automated release pipeline with artifact generation
• Set up documentation generation with GitHub Pages deployment
• Add intelligent issue/PR management with auto-labeling
• Implement comprehensive PR validation with quality checks
• Configure scheduled health checks and maintenance tasks
• Add multi-platform testing and breaking change detection

Complete CI/CD Workflow Suite Implementation

This PR introduces a comprehensive GitHub Actions workflow suite that automates the entire development lifecycle from dependency management to release deployment.

What's Changed

New Workflows Added

• dependency-update.yml - Weekly dependency monitoring with security scanning
• performance-benchmark.yml - Automated performance testing and regression detection
• release.yml - Multi-stage release pipeline with automated asset generation
• documentation.yml - Automated Javadoc generation and GitHub Pages deployment
• issue-management.yml - Intelligent issue/PR labeling and stale content management
• pr-validation.yml - Comprehensive PR analysis with quality and security checks

Key Features

Quality Assurance

• Automated code quality checks (Checkstyle, PMD)
• OWASP security vulnerability scanning
• Test coverage validation and enforcement
• Performance regression detection
• Breaking change analysis

Developer Experience

• Intelligent auto-labeling based on content analysis
• New contributor welcome automation
• Detailed PR feedback with analysis reports
• Comprehensive documentation generation

Automation & Maintenance

• Weekly dependency update monitoring
• Automated release pipeline with GitHub releases
• Stale issue/PR management
• Multi-platform testing coverage

Workflow Triggers

Workflow	Schedule	Events	Manual Dispatch
Dependencies	Weekly (Mon 9AM)	-	✓
Performance	Weekly (Sun 2AM)	Push, PR	✓
Release	-	Version tags	✓
Documentation	-	Push, PR	✓
Issue Management	Daily (12PM)	Issues, PRs	-
PR Validation	-	PR events	-

Benefits

• Reduced Manual Work: Automated dependency updates, releases, and documentation
• Improved Code Quality: Continuous quality checks and security scanning
• Better Maintainability: Automated stale content management and contributor onboarding
• Performance Monitoring: Continuous benchmarking with virtual threads analysis
• Documentation: Always up-to-date docs deployed automatically

Testing

All workflows have been configured with appropriate permissions and include error handling. Manual dispatch triggers are available for testing and maintenance.

Breaking Changes

None - these are new workflow additions that don't affect existing functionality.

Checklist

• Workflows tested with manual dispatch
• Proper permissions configured for each workflow
• Scheduled triggers validated
• Artifact generation tested
• Documentation deployment verified
• Security scanning configuration validated