Ship production optimization M1-M12.5A: queues, metrics, HTTP observability, and vector search reliability.

Keep similar-ai from tripping the global circuit on a lone URL 502, clamp Qdrant search to 100, and add Server-Timing plus slow-request logging. Studio shared props, Academy S3 exists caching, heat chunking, and Redis/scheduler hygiene stay in this rollout.

tests/Feature/Http/ArtworkDownloadMissingFileTest.php

@@ -0,0 +1,24 @@
+<?php
+
+use App\Models\Artwork;
+use App\Services\ArtworkStatsService;
+use Illuminate\Support\Facades\DB;
+
+it('does not increment download stats when the original file is missing', function () {
+    $artwork = Artwork::factory()->create([
+        'is_public' => true,
+        'is_approved' => true,
+        'published_at' => now()->subDay(),
+        'file_name' => 'missing-original.jpg',
+        'file_ext' => 'jpg',
+        'hash' => str_repeat('ab', 32),
+    ]);
+
+    $this->mock(ArtworkStatsService::class, function ($mock) {
+        $mock->shouldReceive('incrementDownloads')->never();
+    });
+
+    $this->get('/download/artwork/'.$artwork->id)->assertNotFound();
+
+    expect(DB::table('artwork_downloads')->where('artwork_id', $artwork->id)->count())->toBe(0);
+});