Write form errors that actually help

For [FORM FIELDS] and [VALIDATION RULES], write field-level errors, a form-level summary and a success confirmation. Each error must state what happened and the next corrective action without blaming the person. Include examples for empty required input, incorrect format, duplicate submission and server failure. Specify focus movement, error association and whether previously entered values remain intact. Return a table of trigger, visible text and assistive-technology announcement. Do not reveal whether a private account exists unless the product's security policy permits it. Avoid vague 'Something went wrong' messages without a recovery route.