chore(portal,operator): upgrade to Nuxt 4

Upgrade both Nuxt apps to Nuxt 4.4.6 (vue-tsc 3, TypeScript 5.6, undici 7) and add a root tsconfig.json to each app. Fix the strict-null / noUncheckedIndexedAccess errors surfaced by Nuxt 4's stricter generated tsconfig and vue-tsc 3. Drop the nuxt-oidc-auth pnpm patch (Nuxt 4 fixes the prepare:types crash natively).

apps/operator/components/Avatar.vue

@@ -15,7 +15,7 @@ const initials = computed(() =>
     .split(' ')
     .filter(Boolean)
     .slice(0, 2)
-    .map((p) => p[0].toUpperCase())
+    .map((p) => p.charAt(0).toUpperCase())
     .join(''),
 )
 

apps/operator/components/UserMenu.vue

@@ -10,7 +10,10 @@ const route = useRoute()
 
 const open = ref(false)
 
-const displayName = computed(() => user.value?.userInfo?.name || user.value?.userName || 'operator')
+const displayName = computed<string>(() => {
+  const name = (user.value?.userInfo as { name?: string } | undefined)?.name
+  return name || (user.value?.userName as string | undefined) || 'operator'
+})
 const email = computed(() => (user.value?.userInfo as { email?: string } | undefined)?.email ?? '')
 
 function toggle() {