:::endpoint POST /v1/admin/tickets/{ticket}/read

The team has read the conversation: every message from the trader, the
assistant and the system that nobody on the team had read yet. It clears
`unread` on the ticket and in the [list](/docs/api/admin/tickets), for the
whole team, as opening a ticket on the website does. Call it when the
conversation is on screen, not when the list loads.

It changes what the team has seen, not the ticket, so it takes `admin:read`
like a read. The trader is never told: read receipts only go the other way.

Answers with how many messages it marked. Nothing left to mark answers `0`.

Needs a firm. Our own staff name one with the `Propper-Workspace` header.

## Request

```bash
curl -X POST "https://api.proppertrading.com/v1/admin/tickets/tkt_cbqjrnz84cq45ca7/read" \
  -H "Authorization: Bearer ptat_9f2c1a44_3b8e7d2f5c9a1b4e6d8f0a2c4e6b8d1f" \
  -H "Propper-Workspace: acme" \
  -H "Idempotency-Key: 8b2f4d6a-1c3e-4a5b-9d7f-0e2c4a6b8d1f"
```

## Response

```json
{
    "data": {
        "object": "ticket_read",
        "marked": 1
    },
    "meta": {
        "request_id": "req_01m50typrk5172p2w9ch2nd1wz"
    }
}
```

## Errors

| Status | Code                      | Meaning                                                                         |
| ------ | ------------------------- | ------------------------------------------------------------------------------- |
| 400    | `workspace_required`      | Asked by our own staff without naming a firm                                    |
| 400    | `missing_idempotency_key` | A POST without an `Idempotency-Key` header                                      |
| 401    | `invalid_token`           | Not a token, or the secret does not match                                       |
| 401    | `revoked_token`           | Signed out here or from another device                                          |
| 401    | `expired_token`           | Ninety days without use, or a set expiry passed                                 |
| 403    | `admin_access_required`   | This account no longer helps run the environment                                |
| 403    | `insufficient_scope`      | This device does not hold `admin:read`                                          |
| 403    | `workspace_not_permitted` | The `Propper-Workspace` header names an environment this account cannot act in |
| 403    | `forbidden`               | Without `view_tickets`                                                          |
| 404    | `resource_not_found`      | No ticket with that id in this firm                                             |