feat: transform to next-level learning platform

New Features:
- ROADMAP.md: Complete 2026 development roadmap
- GETTING_STARTED.md: Quick start guide for beginners
- pyproject.toml: Modern Python project configuration
- .pre-commit-config.yaml: Code quality hooks
- Dockerfile & docker-compose.yml: Container setup
- CI/CD pipeline: GitHub Actions for testing & quality
- tests/test_examples.py: Unit tests for examples
- exercises/: 50+ interactive coding challenges
- tools/validate.py: Automatic exercise validation
- tools/progress.py: Learning progress tracker
- projects/capstone/: Portfolio-worthy projects
- docs/cheat-sheets/: Quick reference guides

Infrastructure:
- Black formatting, Ruff linting configured
- pytest with coverage reporting
- Multi-Python version testing (3.10-3.12)
- Security scanning with Bandit
- Docker development environment

Removed:
- Temporary review documents
- AI-generated issue files

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

Author: hackdartstorm