v0.4.0

v0.4.0 - Chain enum and pubkey format

Better type safety for multi-chain support and public key metadata.

Highlights

• Chain enum (#15): Replaces raw strings with a proper enum. Prepares the library for collections beyond Bitcoin.
• pubkey_format field (#16): Tracks whether a puzzle uses compressed or uncompressed public keys. This matters for address derivation and solving strategy.

❤️ Contributors

• @oritwoen
• @aeitwoen