Biometrics BIOMETRIC AUTHENTICATION (Face ID / Touch ID): - import LocalAuthentication; LAContext().evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics) - Requires NSFaceIDUsageDescription permission (add CONFIG CHANGES) - Check canEvaluatePolicy first; fall back to passcode if biometrics unavailable - LAContext().biometryType to detect .faceID vs .touchID vs .none - Always provide manual unlock alternative (PIN/password) ---