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.

config/metrics.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Hourly artwork metric snapshots (heat, rising, windowed leaderboards).
+ *
+ * Default retention is 30 days so monthly leaderboards and Studio 30d KPIs
+ * have a complete window after warm-up. Override with env; never hardcode.
+ * Studio 30d KPIs use MAX-MIN of cumulative counters, never SUM.
+ */
+return [
+
+    'hourly_snapshot_retention_days' => (int) env('ARTWORK_METRIC_HOURLY_RETENTION_DAYS', 30),
+
+    'hourly_snapshot_prune_chunk' => (int) env('ARTWORK_METRIC_HOURLY_PRUNE_CHUNK', 5000),
+
+    'hourly_snapshot_prune_sleep_ms' => (int) env('ARTWORK_METRIC_HOURLY_PRUNE_SLEEP_MS', 50),
+
+];