描述
Build forms using @mantine/form in the mantine-9 repository. Use this skill when: (1) setting up a form with useForm, (2) adding validation rules or async validation, (3) working with nested object or array fields, (4) sharing form state across components with createFormContext, (5) using uncontrolled mode for performance, (6) using the standalone useField hook, or (7) any task involving useForm, getInputProps, onSubmit, insertListItem, or form validation.