Prefetch artwork prev/next navigation off the critical path.

Move neighbor lookup into a dedicated service and let the viewer load adjacent artworks after first paint instead of blocking the detail request.

app/Http/Controllers/Api/ArtworkNavigationController.php

@@ -5,11 +5,15 @@ namespace App\Http\Controllers\Api;
 use App\Http\Controllers\Controller;
 use App\Http\Resources\ArtworkResource;
 use App\Models\Artwork;
+use App\Services\ArtworkNavigationService;
+use App\Services\ThumbnailPresenter;
 use Illuminate\Http\JsonResponse;
-use Illuminate\Support\Str;
+use Illuminate\Http\Request;
 
 class ArtworkNavigationController extends Controller
 {
+    public function __construct(private readonly ArtworkNavigationService $navigation) {}
+
     /**
      * GET /api/artworks/navigation/{id}
      *
@@ -26,35 +30,11 @@ class ArtworkNavigationController extends Controller
                 'prev_id'   => null, 'next_id'   => null,
                 'prev_url'  => null, 'next_url'  => null,
                 'prev_slug' => null, 'next_slug' => null,
+                'prev_preview' => null, 'next_preview' => null,
             ]);
         }
 
-        $scope = Artwork::published()
-            ->select(['id', 'title', 'slug'])
-            ->where('user_id', $artwork->user_id);
-
-        $prev = (clone $scope)->where('id', '<', $id)->orderByDesc('id')->first();
-        $next = (clone $scope)->where('id', '>', $id)->orderBy('id')->first();
-
-        // Infinite loop: wrap around when reaching the first or last artwork
-        if (! $prev) {
-            $prev = (clone $scope)->where('id', '!=', $id)->orderByDesc('id')->first();
-        }
-        if (! $next) {
-            $next = (clone $scope)->where('id', '!=', $id)->orderBy('id')->first();
-        }
-
-        $prevSlug = $prev ? (Str::slug($prev->slug ?: $prev->title) ?: (string) $prev->id) : null;
-        $nextSlug = $next ? (Str::slug($next->slug ?: $next->title) ?: (string) $next->id) : null;
-
-        return response()->json([
-            'prev_id'   => $prev?->id,
-            'next_id'   => $next?->id,
-            'prev_url'  => $prev ? url('/art/' . $prev->id . '/' . $prevSlug) : null,
-            'next_url'  => $next ? url('/art/' . $next->id . '/' . $nextSlug) : null,
-            'prev_slug' => $prevSlug,
-            'next_slug' => $nextSlug,
-        ]);
+        return response()->json($this->navigation->navigationFor($artwork));
     }
 
     /**
@@ -62,8 +42,12 @@ class ArtworkNavigationController extends Controller
      *
      * Returns full artwork resource by numeric ID for client-side (no-reload) navigation.
      */
-    public function pageData(int $id): JsonResponse
+    public function pageData(Request $request, int $id): JsonResponse
     {
+        if ($request->boolean('prefetch')) {
+            return $this->prefetchData($id);
+        }
+
         $artwork = Artwork::with(['user.profile', 'categories.contentType', 'categories.parent.contentType', 'tags', 'stats'])
             ->published()
             ->find($id);
@@ -73,7 +57,30 @@ class ArtworkNavigationController extends Controller
         }
 
         $resource = (new ArtworkResource($artwork))->toArray(request());
+        $resource['navigation'] = $this->navigation->navigationFor($artwork);
 
         return response()->json($resource);
     }
+
+    private function prefetchData(int $id): JsonResponse
+    {
+        $artwork = Artwork::query()
+            ->published()
+            ->select(['id', 'title', 'slug', 'hash', 'file_path', 'file_name'])
+            ->find($id);
+
+        if (! $artwork) {
+            return response()->json(['error' => 'Not found'], 404);
+        }
+
+        return response()->json([
+            'id' => (int) $artwork->id,
+            'title' => (string) $artwork->title,
+            'slug' => (string) $artwork->slug,
+            'thumbs' => [
+                'md' => ThumbnailPresenter::present($artwork, 'md'),
+                'lg' => ThumbnailPresenter::present($artwork, 'lg'),
+            ],
+        ]);
+    }
 }