feat(admin): View site link next to the user menu

Opens the admin origin's root in a new tab, like the WinterCMS backend.

admin/src/components/shell/AppShell.vue

@@ -6,8 +6,10 @@ import SectionPanel from './SectionPanel.vue'
 import Breadcrumbs from './Breadcrumbs.vue'
 import UserMenu from './UserMenu.vue'
 import Toast from '../ui/Toast.vue'
+import { ExternalLink } from '@lucide/vue'
 import { activeEntry } from '../../state/useNavigation'
 import { useSidebar } from '../../state/useSidebar'
+import { t } from '../../app/i18n'
 
 // Navigation shell (design: Navigation shell and Top header; D-06, D-10):
 // the plugin rail, the active plugin's section panel (hidden when the
@@ -20,6 +22,10 @@ const { collapsed, watchViewport } = useSidebar()
 const stopViewport = watchViewport()
 onBeforeUnmount(stopViewport)
 
+// "View site" (WinterCMS parity) opens the public site in a new tab: the
+// admin page's own origin, without the admin path prefix.
+const siteURL = `${window.location.origin}/`
+
 const active = computed(() => activeEntry(String(route.params.vendor ?? ''), String(route.params.plugin ?? '')))
 </script>
 
@@ -30,7 +36,20 @@ const active = computed(() => activeEntry(String(route.params.vendor ?? ''), Str
     <div class="flex min-w-0 flex-1 flex-col">
       <header class="flex h-header shrink-0 items-center justify-between gap-4 border-b border-border bg-surface pr-6 pl-8">
         <Breadcrumbs />
-        <UserMenu />
+        <div class="flex shrink-0 items-center gap-1">
+          <a
+            data-view-site
+            :href="siteURL"
+            target="_blank"
+            rel="noopener noreferrer"
+            :title="t('backend::lang.nav.view_site')"
+            :aria-label="t('backend::lang.nav.view_site')"
+            class="flex size-input items-center justify-center rounded-inner text-muted transition-colors duration-150 ease-out hover:bg-hover hover:text-text"
+          >
+            <ExternalLink class="size-[18px]" aria-hidden="true" />
+          </a>
+          <UserMenu />
+        </div>
       </header>
       <main class="min-w-0 flex-1 px-8 py-7">
         <slot />