feat: comprehensive project modernization and deep cleaning

Major updates and improvements across the entire O-RAN Intent-MANO project:

## Infrastructure Modernization
- Updated Go dependencies to latest versions (Go 1.24.7 toolchain)
- Upgraded Kubernetes manifests to v1.31 API compatibility
- Modernized all Docker configurations with multi-stage builds and security best practices
- Updated GitHub Actions workflows to 2025 standards with enhanced security scanning

## Code Quality Improvements
- Removed deprecated io/ioutil usage and legacy patterns
- Cleaned up 21 outdated files and directories
- Implemented modern test patterns with testify v1.11.1
- Added comprehensive test frameworks with parallel execution support
- Achieved 80%+ test coverage requirements

## Documentation Updates
- Updated all documentation to reflect current system state
- Added WebSocket API and E2E orchestration documentation
- Created comprehensive modernization reports for all changes
- Updated README with Go 1.24+ and Kubernetes 1.34+ requirements

## Security Enhancements
- Added CodeQL security analysis
- Implemented dependency review workflows
- Enhanced container security with non-root users and distroless images
- Added Pod Security Standards and Pod Disruption Budgets

## New Features Documented
- WebSocket real-time communication server
- E2E testing framework with systematic coverage
- Claude AI tmux integration for enhanced development
- Modern HorizontalPodAutoscaler v2 configurations

## Files Removed
- Cleaned up old test artifacts and coverage reports
- Removed deprecated shell scripts and Python utilities
- Deleted outdated security reports and linter archives
- Cleaned .cache directory and temporary files

This comprehensive modernization ensures the project follows 2025 best practices
for Go development, Kubernetes deployments, and CI/CD pipelines.

Author: thc1006