Summary

This PR delivers the token-row performance foundations from the split plan: a shared useDeferredVisibility hook plus deferred rendering for token tags/address and balance/fiat formatting so the selector only hydrates rows that are near the viewport.

To Test

1. Token selector scrolling

   • Open the token selector on a long network and scroll top-to-bottom; rows should populate smoothly without the earlier jank.
   • Scroll quickly—tags and addresses should appear just before the row enters view, never staying blank once visible.
   • Watch the balance column: a loading shimmer should show off-screen, then switch to formatted balances/fiat once visible.

2. Wallet disconnected

   • Disconnect the wallet and confirm the balance column remains hidden (same as before).

3. Re-filtering

   • Switch chains or update the search query; previously rendered rows should reset their deferred state and only hydrate again after they re-enter the viewport.

Background

Part of the staged token-selector rollout, focusing on deferring expensive row work (logos, tags, fiat) until necessary.