The header decided between profile and login button only from the
server-passed logged prop (read once via cookies() in StLayout), so a
user who logged in client-side still saw ورود | ثبت نام until a hard
reload. Seed isLogged from the server prop (correct first paint, no
hydration mismatch) then sync it from the access_token cookie on mount
and on every route change, so login/logout reflect immediately.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
