Keep the settings rail alive across child navigation

Keying the outer router-view on route.path made every settings click
remount the whole settings shell, resetting the rail scroll to the
top. The key now treats /settings/* as one unit so the shell (and its
scroll position) persists while child pages swap; detail-to-detail
remounts elsewhere are unchanged.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/views/AppLayout.vue

@@ -77,15 +77,16 @@
       </div>
       <!-- Keyed on path so same-component navigation (machine -> machine via
            a relationship link) remounts and reloads; query-only changes
-           (e.g. /reports?report=x) do not remount. -->
-      <router-view :key="route.path" />
+           (e.g. /reports?report=x) do not remount, and the settings shell
+           keys as one unit so its rail survives child navigation. -->
+      <router-view :key="routeViewKey" />
     </main>
     <ToastHost />
   </div>
 </template>
 
 <script setup>
-import { ref, onMounted } from 'vue'
+import { ref, computed, onMounted } from 'vue'
 import { useRouter, useRoute } from 'vue-router'
 import ToastHost from '../components/ToastHost.vue'
 import {
@@ -100,6 +101,9 @@ import { getFacilityName, getSiteLogo, getServicenowUrls } from '../utils/siteSe
 const router = useRouter()
 const route = useRoute()
 const authStore = useAuthStore()
+const routeViewKey = computed(() =>
+  route.path.startsWith('/settings') ? '/settings' : route.path
+)
 const searchQuery = ref('')
 const navItems = ref([])
 const activeNotifications = ref([])