Jon Staab
5364854881
Introduces PublicKey and SecretKey as distinct type-safe wrappers around secp256k1, with hex and NIP-19 bech32 (npub/nsec) encoding. SecretKey has a redacted Debug impl and no Display to reduce accidental leakage; it exposes material only through explicit to_hex / to_nsec. FromStr on both types auto-detects hex vs. bech32. Eight round-trip tests cover encoding, auto-detection, prefix validation, debug redaction, and generation.