Refactor type hints to use modern built-in generics (Python 3.9+)

Currently, the codebase uses legacy typing imports such as:

```python
from typing import List, Tuple, Dict
```

Since Python 3.9 and later support built-in generics, these can be simplified for better readability and future compatibility.

Tasks:
- Replace all instances of List, Tuple, Dict, etc. with built-in generics (list, tuple, dict).
- Remove unnecessary imports from typing.