Keyringseam

Key features

• The provider launches one fixed, signed Broker app per provider lifetime over anonymous pipes.
• It passes no host environment and no command-line arguments to the Broker.
• Every get, set, and unset performs an explicit device-owner authentication.
• Cancellation, timeout, missing entitlements, invalid signatures, locked Keychain, malformed frames, and native failure return errors
• there is no plaintext or legacy-helper fallback.