fix: impersonation UX — banner contrast, route blocking, nav filtering

- Banner: white elevated button for contrast, fixed 48px height,
  layout top padding offset so content isn't obscured
- Middleware: allow GET me/profile (viewing), block mutations only;
  add auth/refresh to blocked routes
- Navigation: hide Platform section during impersonation; hide
  org-dependent items when impersonated user has no organisation
- Test: add read-only routes allowed test, auth/refresh blocked test

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/app/src/layouts/components/DefaultLayoutWithVerticalNav.vue

@@ -1,22 +1,36 @@
 <script lang="ts" setup>
 import { orgNavItems, platformNavItems } from '@/navigation/vertical'
 import { useAuthStore } from '@/stores/useAuthStore'
+import { useImpersonationStore } from '@/stores/useImpersonationStore'
 
 const authStore = useAuthStore()
+const impersonationStore = useImpersonationStore()
+
+const hasOrganisation = computed(() => !!authStore.organisations.length)
 
 const navItems = computed(() => {
   const orgName = authStore.currentOrganisation?.name ?? 'Beheer'
 
-  const orgItems = orgNavItems.map(item => {
+  let orgItems = orgNavItems.map(item => {
     if ('heading' in item && item.heading === 'Beheer') {
       return { ...item, heading: orgName }
     }
     return item
   })
 
-  if (authStore.isSuperAdmin) {
+  // During impersonation: hide org-dependent items if user has no organisation
+  if (impersonationStore.isImpersonating && !hasOrganisation.value) {
+    orgItems = orgItems.filter(item => {
+      if ('heading' in item) return false
+      return 'to' in item && item.to?.name === 'dashboard'
+    })
+  }
+
+  // Platform items: only for super_admin AND only when NOT impersonating
+  if (authStore.isSuperAdmin && !impersonationStore.isImpersonating) {
     return [...orgItems, ...platformNavItems]
   }
+
   return orgItems
 })
 
@@ -35,6 +49,7 @@ import { VerticalNavLayout } from '@layouts'
 </script>
 
 <template>
+  <div :style="{ paddingTop: impersonationStore.isImpersonating ? '48px' : '0' }">
   <VerticalNavLayout :nav-items="navItems">
     <!-- 👉 Organisation switcher -->
     <template #before-vertical-nav-items>
@@ -82,4 +97,5 @@ import { VerticalNavLayout } from '@layouts'
     <!-- 👉 Customizer -->
     <!-- <TheCustomizer /> -->
   </VerticalNavLayout>
+  </div>
 </template>