Get Migration

{
  "migration": {
    "id": "550e8400-e29b-41d4-a716-446655440000",
    "provider": "aws_sm",
    "mode": "pull",
    "status": "awaiting_review",
    "region": "us-east-1",
    "scope": { "regions": ["us-east-1"] },
    "discovered_count": 42,
    "approved_count": 30,
    "rejected_count": 2,
    "committed_count": 0,
    "expired_count": 0,
    "denylisted_count": 1,
    "error_details": null,
    "created_at": "2026-05-20T09:00:00Z",
    "started_at": "2026-05-20T09:00:05Z",
    "completed_at": null
  },
  "items": [
    {
      "id": "item-uuid",
      "source_provider": "aws_sm",
      "source_id": "arn:aws:secretsmanager:us-east-1:111122223333:secret:stripe/prod-abc123",
      "source_path": "stripe/prod",
      "source_region": "us-east-1",
      "source_version": null,
      "source_metadata": {},
      "bucket_classification": "a_https",
      "bucket_classification_source": "heuristic",
      "target_environments": ["production"],
      "status": "pending_review",
      "denylist_reason": null,
      "captured_at": "2026-05-20T09:00:30Z"
    }
  ]
}