feat: define basic app layout

frontend/app/app.vue

@@ -1,6 +1,15 @@
 <template>
     <div>
         <NuxtRouteAnnouncer />
-    <NuxtWelcome />
+
+        <v-app>
+            <NavBar />
+
+            <v-main>
+                <NuxtPage />
+            </v-main>
+
+            <Footer />
+        </v-app>
     </div>
 </template>

frontend/app/pages/index.vue

@@ -0,0 +1,9 @@
+<script setup lang="ts"></script>
+
+<template>
+    <div>
+        Page: index
+    </div>
+</template>
+
+<style scoped></style>