feat(db): add can_create column to system.users

database/create-schema.sql

@@ -375,7 +375,8 @@ CREATE TABLE system.users (
     id smallint NOT NULL,
     name character varying(32) NOT NULL,
     password text NOT NULL,
-    is_admin boolean DEFAULT false NOT NULL
+    is_admin boolean DEFAULT false NOT NULL,
+    can_create boolean DEFAULT false NOT NULL
 );