PatchDraftRequest(PatchDraftRequest)

Validates a PATCH admin/v1/pages/{id}/drafts body. The shape mirrors
the wire format the SPA emits — every node has at minimum a slug
and data (the block's extra_attributes); slot / sort /
status / conditions / children are optional.

Per-block schema validation (color hex, image asset id, etc.) is
handled inside DraftService via BlockDefinition::configSchema()
— wide-net rules here keep the FormRequest readable. Failing schema
checks return 422 with field paths.

{
    "tree": [
        {
            "id": "string",
            "slug": "string",
            "version": "string",
            "slot": "string",
            "sort": 0,
            "status": "enabled",
            "data": [
                "string"
            ],
            "conditions": [
                "string"
            ],
            "children": [
                {
                    "id": "string",
                    "slug": "string",
                    "data": [
                        "string"
                    ]
                }
            ]
        }
    ],
    "page_type": "home"
}