Add auth check to authentiocation package

Frontend/patient_manager/lib/MIH_Packages/authentication/authCheck.dart

@@ -0,0 +1,27 @@
+import 'package:flutter/material.dart';
+import 'package:patient_manager/MIH_Packages/authentication/signInOrRegister.dart';
+import 'package:patient_manager/MIH_Packages/MIH_Home/home.dart';
+import 'package:supertokens_flutter/supertokens.dart';
+
+class AuthCheck extends StatelessWidget {
+  const AuthCheck({super.key});
+
+  Future<bool> doesSessionExist() async {
+    return await SuperTokens.doesSessionExist();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      body: FutureBuilder(
+          future: doesSessionExist(),
+          builder: (context, snapshot) {
+            if (snapshot.data == true) {
+              return const Home();
+            } else {
+              return const SignInOrRegister();
+            }
+          }),
+    );
+  }
+}