fix: add typed AuthError throws to all public AuthClient methods

- Update signOut, verifyOTP, resend, and reauthenticate methods to use throws(AuthError)
- Wrap API calls with wrappingError to ensure proper error type conversion
- Add explicit self references in closures where required
- Ensure consistent error handling across all public methods
- Update _verifyOTP private method to also use throws(AuthError)

This ensures all public methods that can throw errors properly specify AuthError type,
making the API more predictable and type-safe for developers.

Author: grdsdev