feat(contract-document): render the contract details and create the contract document - #1329

…ontract document

The `contract_details` step now renders the country-specific contract details form and
submitting it creates the contract document, then moves the flow to `contract_preview`.

The form is built from `GET /v1/countries/{code}/contractor-contract-details?employment_id=…`
through the shared `useContractorContractDetailsSchema`, so the currencies come from the
contractor and the schema's `default` values prefill the form. Initial values are completed
from the employment's current contract details and provisional start date. The standalone
flow has no pricing-plan step, so the product — Contractor of Record restrictions, the
Contractor Services Agreement disclaimer, the backdating rule — is read off the employment's
`contractor_type`.

The AI misclassification check behaves as in onboarding: a skippable rejection shows the
warning under the field, `canSkipAiValidation` turns true, and submitting again sends
`skip_ai_checks: true`.

New on the bag: `fieldValues`, `checkFieldUpdates`, `handleValidation`, `parseFormValues`,
`onSubmit`, `initialValues`, `meta`, `productIdentifier`, `contractDocumentId`,
`canSkipAiValidation`. New components: `ContractDocumentForm`,
`ContractDocumentSubmitButton`. `options.jsfModify.contract_details` is supported.

Part of pbyr-4778.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

…ord the start-date warning

`ContractDocumentForm` initialised from the employment every time it mounted, so going
back to the step after a submission dropped what had just been entered. It now reads the
step's stored values first, as the onboarding step does.

The start-date mismatch warning referred to the Basic Information step, which the
standalone flow does not have: the shared helper takes the label of the compared date,
and the flow names the contractor's current start date instead. Onboarding keeps its
wording.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

`handleStepError` was called without field metadata, so API field errors surfaced raw
paths like `service_duration/expiration_date`. The hook now prettifies the parsed values
against the schema fields on submit, as the onboarding hook does, and exposes them as
`meta.fields` for the form to hand to `handleStepError`.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

…ht submission

The metadata ref was replaced on submit, but the form's handler had already captured the
bag rendered before, whose `meta.fields` still pointed at the previous empty object. The
ref now holds one object mutated per step, as the onboarding hook does, so the handler
reads the labels computed for the submission it is reporting on.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

…error response

The shared schema query resolved an error response as a success, so a 403 or 5xx built
an empty form and the flow reported itself ready with no fields and a live submit button.
The query now throws on `response.error`, as the countries and contract-documents queries
do.

Tests answer the schema endpoint by default so the standalone flow tests no longer run
through an unhandled request, and two behaviours are pinned: entered contract details are
restored when coming back from the preview, and a Contractor of Record is not shown the
Contractor Services Agreement disclaimer.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

The standalone flow copied onboarding and prefilled the start date with the employment's
provisional start date. For an existing contractor that date is in the past, which on the
Plus and Contractor of Record plans immediately raised the backdating warning. The Remote
platform prefills today's date for a new contract document, so the flow does the same.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

…andalone flow

The note compares the start date with the one given at the Basic Information step and
warns when they differ. In the standalone flow the contractor already exists and the field
is prefilled with today, so the note would show on nearly every open. The shared helper
is back to its onboarding-only signature.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

…ission when the form cannot load

Throwing from the schema query only left data undefined: the bag still reported
isLoading false with no fields, so the submit button stayed enabled and a click
sent an empty contract document. The bag now exposes the first error among the
employment, contract-documents and schema queries, and the submit button is
disabled while one is set.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

…ractor fallback

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

…ontractor

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

…ay as the start date

The employment query resolves with no employment on an error response, so the
bag reported no error and the submit button stayed enabled with an empty form.
The bag now surfaces that as an error. The stored contract details used to
override today's start date; today now wins, as the platform does and as the
README states.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

…ning

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

… helpers from their old paths

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

…nts list cannot load

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>