feat(redux): Rename all Redux slices and store keys to match file names for clarity

- Renamed all slice names (createSlice `name` attribute) to match their file names (e.g. loopChartSlice, authSlice, kueDataSlice etc.)
- Updated `store.ts` to register each reducer with consistent key names (e.g. state.loopChartSlice instead of state.loopChart)
- Adjusted all `useSelector` and Redux state accesses across the codebase
- Improves maintainability, searchability and consistency across files and Redux DevTools

redux/slices/last20MessagesSlice.ts

@@ -10,7 +10,7 @@ const initialState: Last20MessagesSlice = {
 };
 
 export const last20MessagesSlice = createSlice({
-  name: "last20Messages",
+  name: "last20MessagesSlice",
   initialState,
   reducers: {
     setLast20Messages: (state, action: PayloadAction<string | null>) => {