Add post status change notifications and set up Git push

Installs `expo-notifications` and `expo-task-manager` packages. Implements a `useNotifications` hook for requesting permissions, polling for post status changes, and sending local notifications for published or errored posts. Updates `app.json` to include notification permissions and the notification handler. Wires the `useNotifications` hook into the app's root layout.

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artifacts/postiz-mobile/app/_layout.tsx

@@ -15,6 +15,7 @@ import { SafeAreaProvider } from "react-native-safe-area-context";
 
 import { ErrorBoundary } from "@/components/ErrorBoundary";
 import { PostizProvider } from "@/context/PostizContext";
+import { useNotifications } from "@/hooks/useNotifications";
 
 SplashScreen.preventAutoHideAsync();
 
@@ -27,6 +28,11 @@ const queryClient = new QueryClient({
   },
 });
 
+function NotificationBootstrap() {
+  useNotifications();
+  return null;
+}
+
 function RootLayoutNav() {
   return (
     <Stack screenOptions={{ headerBackTitle: "Back" }}>
@@ -56,6 +62,7 @@ export default function RootLayout() {
       <ErrorBoundary>
         <QueryClientProvider client={queryClient}>
           <PostizProvider>
+            <NotificationBootstrap />
             <GestureHandlerRootView style={{ flex: 1 }}>
               <KeyboardProvider>
                 <RootLayoutNav />