feat(ui): custom confirmation dialog replacing native window.confirm

Single reusable dialog with a promise-based API: confirmAction({...})
returns Promise<boolean>. Supports title, optional message body,
confirm/cancel labels, and a 'destructive' flag that paints the confirm
button red.

Accessibility: Escape cancels, Enter confirms, confirm button auto-focus,
role=dialog + aria-labelledby, backdrop click = cancel.

Rolled out to: recipe delete, domain remove, profile delete, wishlist
remove. Native confirm() is gone from the codebase.

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

src/routes/admin/domains/+page.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import { onMount } from 'svelte';
   import type { AllowedDomain } from '$lib/types';
+  import { confirmAction } from '$lib/client/confirm.svelte';
 
   let domains = $state<AllowedDomain[]>([]);
   let loading = $state(true);
@@ -38,9 +39,15 @@
     await load();
   }
 
-  async function remove(id: number) {
-    if (!confirm('Domain entfernen?')) return;
-    await fetch(`/api/domains/${id}`, { method: 'DELETE' });
+  async function remove(d: AllowedDomain) {
+    const ok = await confirmAction({
+      title: 'Domain entfernen?',
+      message: `${d.domain} wird nicht mehr durchsucht. Gespeicherte Rezepte bleiben erhalten.`,
+      confirmLabel: 'Entfernen',
+      destructive: true
+    });
+    if (!ok) return;
+    await fetch(`/api/domains/${d.id}`, { method: 'DELETE' });
     await load();
   }
 
@@ -80,7 +87,7 @@
           <div class="dom">{d.domain}</div>
           {#if d.display_name}<div class="label">{d.display_name}</div>{/if}
         </div>
-        <button class="btn danger" onclick={() => remove(d.id)}>Löschen</button>
+        <button class="btn danger" onclick={() => remove(d)}>Löschen</button>
       </li>
     {/each}
   </ul>