CI gate and acknowledgements

{
  "passing": false,
  "unacknowledged": [
    {
      "signal_id": "8f2f90c9-7fd5-4d9d-9c90-2df870dd3a2a",
      "signal_type": "api_change",
      "severity": "breaking",
      "summary": "A required request parameter changed type."
    }
  ]
}

curl --request POST "$LUCIM_API_URL/v1/signals/$SIGNAL_ID/acknowledge" \
  --header "Authorization: Bearer $LUCIM_API_KEY"

{
  "signal_id": "8f2f90c9-7fd5-4d9d-9c90-2df870dd3a2a",
  "acknowledged_at": "2026-07-15T19:00:00Z"
}