CHW-4701 WebhookRequestBodyInvalid

webhook request body was missing or malformed; supply a JSON object with url (and optionally enabled) fields

Default message: webhook request body was missing or malformed; supply a JSON object with url (and optionally enabled) fields
HTTP status: 400 (client)

Problem. POST /api/webhooks or PATCH /api/webhooks/{id} rejected the body with 400. Cause. The JSON could not be decoded or the required url field was missing from a create payload. Fix. Send a JSON object of shape {"url":"https://...","enabled":true} on create; send a subset of those fields on patch. HTTP 400.