PythonSTL: Replicating C++ STL Semantics via a Dual-Engine Python-Rust Hybrid System

Replicating C++ Standard Template Library containers and algorithms in Python, dynamically delegating operations between a pure-Python fallback (using AVL trees) and an optimized, compiled Rust backend (using B-trees via PyO3/Maturin) to showcase hybrid architecture patterns and FFI optimization trade-offs.