[feat] Improve Configuration Management

[san-ghun]

The settings management could be improved by:

• Adding configuration file validation
• Supporting environment variables override
• Implementing a proper config parser

Example enhancement for settings.py:

import os
import yaml
from pathlib import Path
from typing import Optional, Dict, Any

def load_config() -> Dict[str, Any]:
    """Load configuration from multiple sources."""
    # Default config
    config = {
        'workspace': os.path.join(os.environ['HOME'], 'Projects/42berlin'),
        'echo_on_startup': True,
        'port_publishing': False,
        'port_host': 8080,
        'port_container': 8080
    }
    
    # Override from config file
    config_file = Path.home() / '.config' / 'tiny42' / 'config.yaml'
    if config_file.exists():
        with open(config_file) as f:
            config.update(yaml.safe_load(f))
    
    # Override from environment variables
    if 'TINY42_WORKSPACE' in os.environ:
        config['workspace'] = os.environ['TINY42_WORKSPACE']
    
    return config

---

I haven't checked whether the yaml module is a standard module in Python3 or not, as a requirement of the project is to keep external dependencies as low as possible, so I'll switch to using the json module if necessary.