feat(ui): custom dialog replaces all remaining window.alert() calls

alertAction({title, message}) returns Promise<void> and renders the
same ConfirmDialog with infoOnly:true — single OK button, no Abbrechen.
Replaces:
- 'Bitte Profil wählen.' (recipe rating / favorite / cooked / comment)
- 'Bitte Profil wählen, um zu liken.' (wishlist)
- 'Profil konnte nicht angelegt werden' (ProfileSwitcher)
- 'Umbenennen fehlgeschlagen' (admin/profiles)
- 'Speichern fehlgeschlagen' (preview)

No window.alert() or window.confirm() left in the codebase.

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

src/routes/wishlist/+page.svelte

@@ -1,7 +1,7 @@
 <script lang="ts">
   import { onMount } from 'svelte';
   import { profileStore } from '$lib/client/profile.svelte';
-  import { confirmAction } from '$lib/client/confirm.svelte';
+  import { confirmAction, alertAction } from '$lib/client/confirm.svelte';
   import type { WishlistEntry, SortKey } from '$lib/server/wishlist/repository';
 
   let entries = $state<WishlistEntry[]>([]);
@@ -27,7 +27,10 @@
 
   async function toggleLike(entry: WishlistEntry) {
     if (!profileStore.active) {
-      alert('Bitte Profil wählen, um zu liken.');
+      await alertAction({
+        title: 'Kein Profil gewählt',
+        message: 'Tippe oben rechts auf „Profil wählen", um zu liken.'
+      });
       return;
     }
     const method = entry.liked_by_me ? 'DELETE' : 'PUT';