style(admin): Emoji-Icons durch Lucide-Icons ersetzt

🌐/👥/💾 waren die letzten verbliebenen Emoji-Icons in der App und
stachen gegen die Lucide-Icons im Rest heraus. Jetzt Globe/Users/
DatabaseBackup als SVG-Icons in den Admin-Tabs, passt zum übrigen
Design.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/routes/admin/+layout.svelte

@@ -1,23 +1,26 @@
 <script lang="ts">
   import { page } from '$app/stores';
+  import { Globe, Users, DatabaseBackup, type Icon } from 'lucide-svelte';
 
   let { children } = $props();
 
-  const items = [
-    { href: '/admin/domains', label: '🌐 Domains' },
-    { href: '/admin/profiles', label: '👥 Profile' },
-    { href: '/admin/backup', label: '💾 Backup' }
+  const items: { href: string; label: string; icon: typeof Icon }[] = [
+    { href: '/admin/domains', label: 'Domains', icon: Globe },
+    { href: '/admin/profiles', label: 'Profile', icon: Users },
+    { href: '/admin/backup', label: 'Backup', icon: DatabaseBackup }
   ];
 </script>
 
 <nav class="tabs">
   {#each items as item (item.href)}
+    {@const Icon = item.icon}
     <a
       href={item.href}
       class="tab"
       class:active={$page.url.pathname.startsWith(item.href)}
     >
-      {item.label}
+      <Icon size={16} strokeWidth={2} />
+      <span>{item.label}</span>
     </a>
   {/each}
 </nav>
@@ -35,7 +38,7 @@
     -webkit-overflow-scrolling: touch;
   }
   .tab {
-    padding: 0.6rem 0.9rem;
+    padding: 0.5rem 0.95rem 0.5rem 0.8rem;
     background: white;
     border: 1px solid #e4eae7;
     border-radius: 999px;
@@ -46,6 +49,7 @@
     min-height: 40px;
     display: inline-flex;
     align-items: center;
+    gap: 0.4rem;
   }
   .tab.active {
     background: #2b6a3d;