added unique fields

examples/basic/data/users.jsonl

@@ -0,0 +1,2 @@
+{"age":31,"created":"2026-03-04T09:07:22+06:00","email":"john@example.com","id":1,"name":"John Doe"}                                                                                                                                                                                                                                                                                                                                                                                                                           
+{"age":35,"created":"2026-03-04T09:07:22+06:00","email":"bob@example.com","id":3,"name":"Bob Johnson"}