switch artist_usage pk from role to artist_role_id

misc/my-migrations/20250619000000_artist_usage_pkey.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+use Phinx\Migration\AbstractMigration;
+
+final class ArtistUsagePkey extends AbstractMigration {
+    public function up(): void {
+        $this->query("
+            alter table artist_usage
+                drop primary key,
+                add primary key (artist_id, artist_role_id),
+                modify role enum ('1','2','3','4','5','6','7','8')
+        ");
+    }
+
+    public function down(): void {
+        $this->query("
+            alter table artist_usage
+                drop primary key,
+                add primary key (artist_id, role),
+                modify role enum ('1','2','3','4','5','6','7','8') NOT NULL
+        ");
+    }
+}