perf: adopt optimistic state updates and avoid blocking UI for level operations

in the future we'll want a layer that:

- asynchronously updates `level` under the hood (but doesn't block render)
- adopts optimistic updates in order to increase the perception of speed in the UI
- reads from a memory based store (like React Query)
- we'll want to finetune when and how react query rehydrates from level
- react query should not block the UI when it rehydrates from level