Changes:

• Added QueryClient and QueryClientProvider.
• Pokémon list is now fetched through useQuery.
• Removed the previous manual in-memory cache.
• Search now filters the fetched Pokémon list locally instead of making a new API request for each search.
• Loading and API error states are now handled using TanStack Query.
• Removed the old searchPokemon implementation that was no longer necessary.

Tested the changes with:

• npm run lint and npm run build.
• Manual testing of Pokémon search, error and empty states, and favorites.