v0.1.1

Fixed

• getVerificationKeyPair() now throws when the key pair lacks a private key
  instead of returning a descriptor with privateKeyMultibase: undefined.
• secret is typed as required on fromSecret() and seedFromSecret(),
  matching the runtime check. The JSDoc no longer refers to a nonexistent
  cache option.

Changed

• The key-name HMAC step uses SHA256HMACKey from
  @interop/data-integrity-core instead of a local WebCrypto call. Derivation
  output is unchanged.
• Derived key pairs carry controller (the agent's did:key) alongside id.
• getVerificationKeyPair() returns the key fields (id, type, controller,
  publicKeyMultibase, privateKeyMultibase) as a plain object instead of
  going through the VerificationKey2020 exporter. The shape is unchanged; the
  return type is inlined and the VerificationKeyDescriptor export is gone.

Removed

• The VerificationKeyDescriptor type export. Use the inferred return type of
  getVerificationKeyPair().