AppleWebAuthnProvider

Apple-native WebAuthn provider using AuthenticationServices framework.

This provider implements WebAuthn passkey operations for iOS 16+ and macOS 13+ using Apple's ASAuthorizationPlatformPublicKeyCredentialProvider. It provides biometric-secured credential creation and assertion for Stellar smart account operations.

The provider handles:

• Passkey creation with platform authenticator (Touch ID / Face ID)

• Passkey assertion for transaction signing

• Automatic public key extraction from attestation data

• Proper bridging of delegate callbacks to Kotlin coroutines

Usage:

val provider = AppleWebAuthnProvider(
    rpId = "example.com",
    rpName = "My Stellar Wallet"
)

val config = OZSmartAccountConfig.builder(...)
    .webauthnProvider(provider)
    .build()

Note on macOS: ASAuthorizationController requires a presentation context provider (ASAuthorizationControllerPresentationContextProviding) to specify the window in which to present the authorization sheet. On iOS this is handled automatically. On macOS, callers should set the presentationContextProvider on the controller via a platform-specific integration point (e.g., a SwiftUI bridge or AppKit delegate). A future API revision may accept an optional presentation context parameter.