How does TanStack Query manage its query cache, stale time, and background refetching — and how do you tune these for a high-traffic dashboard?

Imagine you have a toy box. TanStack Query is like a helper that remembers which toys you played with recently, so you don't have to search for them again. It also knows when a toy might be old and needs to be checked again, like when your friend says 'that toy is boring now'.