create-form-data-handlinglisted

# create-form-data-handling Read `@.ai/Component/Forms/CONTEXT.md` for form conventions (IdentifiableObject pattern, service registration). ## 1. DataProvider Create `src/Core/Form/IdentifiableObject/DataProvider/{Domain}FormDataProvider.php` implementing `FormDataProviderInterface`: - `getData(int $id): array` — dispatch `Get{Domain}ForEditing` query via query bus, map the result DTO to the form's expected array structure - `getDefaultData(): array` — return sensible defaults for the create form (empty strings, null IDs, `active => true`) - Both methods must return the same array structure — the form type cannot distinguish create from edit - Multilingual fields: return arrays keyed by integer language ID **Reference:** `src/Core/Form/IdentifiableObject/DataProvider/TaxFormDataProvider.php` (simple) ## 2. DataHandler Create `src/Core/Form/IdentifiableObject/DataHandler/{Domain}FormDataHandler.php` implementing `FormDataHandlerInterface`: - `create(array $data): mixed` — build `Add{Domain}Command` from `$data`, dispatch via command bus, return new entity ID - `update(int $id, array $data): void` — build `Edit{Domain}Command($id)`, call fluent setters for each field from `$data`, dispatch - Map form array keys to command setters: `$command->setName($data['name'])` - Multilingual: `$command->setLocalizedNames($data['name'])` where value is lang-keyed array - Sub-resource commands dispatched separately (see [Forms/CONTEXT.md](../../CONTEXT.md) for dispatch order) **Refe