Add artifact name suggestions for download and install commands

src/StaticPHP/Registry/ArtifactLoader.php

@@ -69,6 +69,17 @@ class ArtifactLoader
         }
     }
 
+    /**
+     * Get names of all loaded artifacts.
+     *
+     * @return string[]
+     */
+    public static function getLoadedArtifactNames(): array
+    {
+        self::initArtifactInstances();
+        return array_keys(self::$artifacts ?? []);
+    }
+
     /**
      * Process #[CustomSource] attribute.
      */