add basic user authentication

front/src/auth.store.js

@@ -0,0 +1,21 @@
+import { defineStore } from 'pinia';
+import { useRouter } from 'vue-router'
+
+export const useAuthStore = defineStore('auth', {
+  state: () => ({
+    // initialize state from local storage to enable user to stay logged in
+    user: JSON.parse(localStorage.getItem('user')),
+    returnUrl: null
+  }),
+  actions: {
+    login(user) {
+      this.user = user;
+      localStorage.setItem('user', JSON.stringify(user));
+    },
+    logout() {
+      this.user = null;
+      localStorage.removeItem('user');
+      useRouter().push('/');
+    }
+  }
+});