feat(ui): wishlist page, recipe toggle button, header link

- /wishlist renders cards with avatar-badge of who added it, like count,
  heart toggle for active profile, delete button. Sort dropdown switches
  between popular / newest / oldest.
- /recipes/[id] gets 'Auf Wunschliste (setzen)' button alongside favorite.
- Layout header shows 🍽️ link to /wishlist next to the admin ⚙️.

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

src/routes/recipes/[id]/+page.svelte

@@ -13,6 +13,7 @@
   let comments = $state<CommentRow[]>([]);
   let cookingLog = $state<typeof data.cooking_log>([]);
   let isFav = $state(false);
+  let onWishlist = $state(false);
   let newComment = $state('');
 
   $effect(() => {
@@ -124,6 +125,31 @@
     location.reload();
   }
 
+  async function toggleWishlist() {
+    if (onWishlist) {
+      await fetch(`/api/wishlist/${data.recipe.id}`, { method: 'DELETE' });
+      onWishlist = false;
+    } else {
+      await fetch('/api/wishlist', {
+        method: 'POST',
+        headers: { 'content-type': 'application/json' },
+        body: JSON.stringify({
+          recipe_id: data.recipe.id,
+          profile_id: profileStore.active?.id ?? null
+        })
+      });
+      onWishlist = true;
+    }
+  }
+
+  async function refreshWishlistState() {
+    // No dedicated GET for a single entry; scan the list and check.
+    const res = await fetch('/api/wishlist?sort=newest');
+    if (!res.ok) return;
+    const body = await res.json();
+    onWishlist = body.entries.some((e: { recipe_id: number }) => e.recipe_id === data.recipe.id);
+  }
+
   // Wake-Lock
   let wakeLock: WakeLockSentinel | null = null;
   async function requestWakeLock() {
@@ -139,6 +165,7 @@
   onMount(() => {
     void requestWakeLock();
     void checkFavorite();
+    void refreshWishlistState();
     const onVisibility = () => {
       if (document.visibilityState === 'visible' && !wakeLock) void requestWakeLock();
     };
@@ -171,6 +198,9 @@
         <button class="btn" class:heart={isFav} onclick={toggleFavorite}>
           {isFav ? '♥' : '♡'} Favorit
         </button>
+        <button class="btn" class:wish={onWishlist} onclick={toggleWishlist}>
+          {onWishlist ? '✓' : '🍽️'} {onWishlist ? 'Auf Wunschliste' : 'Auf Wunschliste setzen'}
+        </button>
         <button class="btn" onclick={() => window.print()}>🖨 Drucken</button>
         <button class="btn" onclick={renameRecipe}>✎ Umbenennen</button>
         <button class="btn danger" onclick={deleteRecipe}>🗑 Löschen</button>
@@ -267,6 +297,11 @@
     border-color: #f1b4b4;
     background: #fdf3f3;
   }
+  .btn.wish {
+    color: #2b6a3d;
+    border-color: #b7d6c2;
+    background: #eaf4ed;
+  }
   .btn.primary {
     background: #2b6a3d;
     color: white;