azure-ad-sso-deferred-v1-uses-local-auth

Azure AD SSO was initially selected as the sole IdP for R-Same but was amended to be deferred because Runwal’s AD infrastructure is not yet complete. v1 ships with local auth only: argon2id + TOTP MFA (mandatory) + JWT in httpOnly cookies. ADR-0003 records this decision. Stub interfaces for Azure AD OIDC/SAML2 are wired in v1; migration path is dual-mode → per-user email-match → deprecate local when AD is ready.