v1.1.0 of darto_auth

Authentication for the Darto web framework — password hashing (PBKDF2), session-based auth, and OAuth 2.0 / OpenID Connect (Google, GitHub). Changelog excerpt: - OAuth 2.0 / OIDC— OAuthProviderwith PKCE S256 on by default, randomised state(CSRF), Authorization-Code flow exchange and a pluggable userMapper. - OAuthProvider.oidc(issuer: ...)— async factory that discovers the authorization, token and userinfo endpoints from .well-known/openid-configuration. - Pre-configured OAuthProvider.google(...)(via OIDC) and OAuthProvider.github(...)factories. - provider.attach(app, prefix, onSignIn: ...)— registers GET (redirect) and `G[...]