Redux Toolkit

Summary

The official, modern way to write Redux — reducing boilerplate with `createSlice`, `configureStore` and built-in Immer for 'mutating' state safely.

• 1Build a simple slice (e.g. a cart) with `createSlice` and connect it to a component.
• 2Learn `createAsyncThunk` for handling async actions like API calls.
• 3Understand why Redux Toolkit replaced writing Redux 'by hand' for most teams.