fix: Windows client compile errors — get_world_3d on Node, array type mismatch, null plugin guard, maps format

server/scripts/plugin_api/plugin_manager.gd

@@ -251,6 +251,9 @@ func _load_plugin_from_manifest(name: String, manifest: PluginManifest) -> bool:
 		if "plugin_author" in instance:
 			instance.plugin_author = manifest.author
 
+	if instance == null:
+		push_error("[PluginManager] Failed to instantiate plugin: %s" % name)
+		return
 	instance.name = "Plugin_%s" % name
 	add_child(instance)
 	loaded_plugins[name] = instance