Moved categories to its own configuration file

hooks/useNotificationListener.ts

@@ -1,6 +1,7 @@
 import AsyncStorage from "@react-native-async-storage/async-storage";
 import * as Notifications from "expo-notifications";
 import { useEffect } from "react";
+import { Category, categoryKeys } from "types/Category";
 import { Item } from "types/Item";
 
 const STORAGE_KEY = "notifications-data";
@@ -50,10 +51,12 @@ export function useNotificationListener(onItems: (items: Item[]) => void) {
 function mapNotificationToItem(notification: Notifications.Notification): Item | null {
 	try {
 		const content = notification.request.content;
+		const rawCategory = content.data?.category as Category | undefined;
+		const category: Category = rawCategory && categoryKeys.includes(rawCategory) ? rawCategory : "home";
 
 		return {
 			timestamp: Date.now(), // could use backend timestamp if provided
-			category: (content.data?.category as Item["category"]) ?? "home",
+			category,
 			title: content.title ?? "No title",
 			info: content.body ?? "No details",
 			link: (content.data?.link as string) ?? "",
@@ -64,6 +67,8 @@ function mapNotificationToItem(notification: Notifications.Notification): Item |
 	}
 }
 
+export { mapNotificationToItem };
+
 // Save a new item into storage and update state
 async function addItem(item: Item, onItems: (items: Item[]) => void) {
 	try {