JR isn't letting me send `meta` as a record property, despite it allows in jsonapi.org

Data:

> POST /v1/ayments HTTP/1.1
> Host: commerce.laurelandwolf.local
> Accept-Encoding: deflate, gzip
> Content-Type: application/vnd.api+json
> Accept: application/vnd.api+json
> Content-Length: 364
| {
| 	"data": {
| 		"type": "payments",
| 		"attributes": {
| 			"token": "tok_visa"
| 		},
| 		"relationships": {
| 			"chargeable": {
| 				"data": {
| 					"id": "1",
| 					"type": "requests"
| 				}
| 			}
| 		},
| 		"meta": {
| 			"request": {
| 				"shipping-cents": 10000,
| 				"shipping-currency": "USD"
| 			}
| 		}
| 	}
| }

Response:

{
	"errors": [
		{
			"title": "Param not allowed",
			"detail": "meta is not allowed.",
			"code": "105",
			"status": "400"
		}
	]
}

jsonapi.org specification:

Creating Resources

A resource can be created by sending a POST request to a URL that represents a collection of resources. The request MUST include a single resource object as primary data. The resource object MUST contain at least a type member.

Resource Objects

"Resource objects" appear in a JSON API document to represent resources.

A resource object MUST contain at least the following top-level members:

• id
• type

Exception: The id member is not required when the resource object originates at
the client and represents a new resource to be created on the server.

In addition, a resource object MAY contain any of these top-level members:

• attributes: an [attributes object][attributes] representing some of the resource's data.
• relationships: a [relationships object][relationships] describing relationships between
  the resource and other JSON API resources.
• links: a [links object][links] containing links related to the resource.
• meta: a [meta object][meta] containing non-standard meta-information about a
  resource that can not be represented as an attribute or relationship.

Reproduce the POST request from the issue and trace how the resource object's top-level members are validated. Confirm the JSON:API resource-object handling rejects meta, then add coverage for this payload and verify that a valid resource with meta is accepted.