Pick up an account that just finished connecting

Asks the provider what accounts exist and records any this org is missing, attributing each to whoever started connecting it. Exists because the connect callback is an inbound request to a URL we hand the provider — it never arrives on localhost or a preview deployment, and can be missed in production, leaving an account connected on their side and invisible here. Idempotent: an account already held is skipped.

curl -X POST "https://loading/api/v1/org/mailboxes/sync"

{
  "data": {
    "claimed": -9007199254740991,
    "unclaimed": -9007199254740991
  }
}

{
  "error": "string",
  "message": "string",
  "statusCode": -9007199254740991
}

{
  "error": "module_required",
  "module": "string",
  "message": "string",
  "contact": "string"
}

{
  "error": "string",
  "message": "string",
  "statusCode": -9007199254740991
}