- Added core caching functionality with `Cache` class supporting in-memory and file-based caching.
- Introduced `CacheManager` for high-level cache operations and statistics.
- Created various cache key generation strategies: `FilepathMethodStrategy`, `APIRequestStrategy`, `SimpleKeyStrategy`, and `CustomStrategy`.
- Developed decorators for easy method caching: `cached`, `cached_method`, `cached_api`, and `cached_property`.
- Implemented type definitions for cache entries and statistics.
- Added comprehensive tests for cache operations, strategies, and decorators to ensure functionality and backward compatibility.