Authentication Patterns Overview This skill covers authentication and authorization implementation across web and mobile applications. It addresses OAuth 2.0 flows (Authorization Code with PKCE, Client Credentials), JWT management (access tokens, refresh tokens, rotation), session management strategies, multi-factor authentication (TOTP, WebAuthn/passkeys), integration with auth libraries (NextAuth/Auth.js v5, Clerk, Supabase Auth, Lucia), SSO protocols (SAML, OIDC), and authorization patterns (RBAC, ABAC). Use this skill when building login/signup flows, integrating social login providers, i…