btc-vision/as-bignum

The `@btc-vision/as-bignum` library provides high-performance fixed-length big number support for AssemblyScript and WebAssembly, offering types like `u128`, `u256`, `i128`, and `i256` with full arithmetic operations. It's designed specifically for blockchain smart contracts and cryptographic operations where deterministic behavior with large integers is critical, and explicitly warns against using floating-point arithmetic which is prohibited in blockchain environments.