fix: use isomorphic layout effect in useCookies to suppress SSR warning - #949

Problem

useCookies calls useLayoutEffect unconditionally, causing React to emit a useLayoutEffect does nothing on the server warning in every SSR-enabled app. The effect body already guards against running server-side with if (!isInBrowserEnv) return, so this is purely log noise.

Fix

Replace useLayoutEffect with an isomorphic variant that falls back to useEffect on the server — the standard pattern used by Chakra UI, MUI, Framer Motion, etc. No behaviour changes on the client.