Add photo management for models and employees; fix stale detail navigation

Model photos: upload/replace/delete on /api/models/<id>/image (admin),
stored under instance/modelimages/ with a public serve route; thumbnail
plus Upload/Replace/Remove controls in the Models settings modal; the
URL field remains as a manual alternative.

Employee photos, mode-aware: self-hosted directory employees get
upload/replace/delete (photo-<sso> under instance/employeephotos/,
employees plugin migration 0002); external directory mode passes the
HR-supplied picture URL through read-only (writes 409). One resolver
feeds both consumers - the shopfloor recognition/recert kiosk cards and
the employee detail hero - in either mode.

Navigation fix: router-view is keyed on route path, so following a
relationship link between two assets of the same type (machine ->
dualpath machine) reloads the page instead of showing stale content;
query-only URL changes still avoid a remount.

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

frontend/src/views/AppLayout.vue

@@ -75,7 +75,10 @@
           </span>
         </div>
       </div>
-      <router-view />
+      <!-- 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" />
     </main>
     <ToastHost />
   </div>
@@ -83,7 +86,7 @@
 
 <script setup>
 import { ref, onMounted } from 'vue'
-import { useRouter } from 'vue-router'
+import { useRouter, useRoute } from 'vue-router'
 import ToastHost from '../components/ToastHost.vue'
 import {
   Sun, Moon, LayoutDashboard, Calendar, Map, Cog, Monitor,
@@ -95,6 +98,7 @@ import { dashboardApi, notificationsApi } from '../api'
 import { getFacilityName, getSiteLogo, getServicenowUrls } from '../utils/siteSettings'
 
 const router = useRouter()
+const route = useRoute()
 const authStore = useAuthStore()
 const searchQuery = ref('')
 const navItems = ref([])