Queue jobs include campaign and recipient identifiers for traceability

A job payload containing only {to, subject, html} becomes useless the moment it lands in the DLQ. Without a campaign ID, a recipient ID, and a correlation key, you cannot answer which campaign generated the failure, which contact never received the message, or whether the failure was isolated or systemic. ISO-25010:2011 maintainability.analysability requires that system faults can be diagnosed from the available artifacts — an untraceable job payload defeats that entirely, forcing triage through raw log searches across worker instances.

Include all three traceability fields at the point of enqueue in lib/queue.ts or wherever campaign sends are dispatched:

await emailQueue.add('send', {
  campaignId: campaign.id,
  recipientId: contact.id,
  correlationId: `${campaign.id}:${contact.id}`,
  templateId: template.id,
  to: contact.email,
  mergeFields: { firstName: contact.firstName }
})

In the worker, log all three fields on both success and failure paths so correlation IDs appear in structured log queries.