Stop using Redux for client-side state management

[akirabaruah]

It seems like overkill for this project's use case.

It's questionable whether we need complex client-side state management at all, since the app is very CRUD-y. In #714 (comment), I mentioned HTMX as an option to reduce complexity and keep state entirely in the backend as the source of truth.

Another less-invasive option might be to use Zustand (https://github.com/pmndrs/zustand) instead of Redux as a lighter weight client state management solution.