Non-custodial wallet registration. The caller provides the on-chain address and the Dilithium3 public key. The custody service never holds private keys.
API key authentication. Format: Bearer {key_id}:{secret}
Idempotency key for safe retries (required for POST/PUT)
Wallet registered
^0x[a-fA-F0-9]{40}$ACTIVE, ARCHIVED Hex-encoded Dilithium3 public key (1952 bytes)