WebGPU mining runner.

The implementation wires a compute shader that performs the full double-SHA256 over tx_prefix || nonce || tx_suffix. The shader mirrors the CPU implementation in zeldhash-miner-core and returns txids in the same byte order (big-endian hash bytes, which callers treat as txid by reversing when counting leading zeros). Storage buffer layouts match the TODO design so the JavaScript bindings and future optimizations can reuse them unchanged.

zeldhash-miner-gpu

WebGPU mining backend for the Zeldhash miner.

Learn more at https://zeldhash.com.