Identity (6 tests):
- Same seed → same Ed25519/X25519 keys, same fingerprint, same display
- Random seed, raw HKDF output verified
BIP39 Mnemonic (3 tests):
- Roundtrip both directions, identical strings
CallSignal Interop (4 tests):
- Offer/Answer/Hangup roundtrip through FC bincode serialization
- Signal type mapping verified
Auth Contract (2 tests):
- Request/response shapes match between WZP and FC
Uses warzone-protocol v0.0.21 as real dependency.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>