duplicate key audit derived

{
  "input": {
    "body": {
      "csv": "email,signed_up\nAda@Example.test,2026-01-01\nada@example.test,2026-02-01\nada@example.test ,2026-03-01\ngrace@example.test,2026-01-05\ngrace@example.test,2026-04-01\n",
      "key": [
        "email"
      ],
      "normalise": [
        "lowercase",
        "trim"
      ]
    },
    "type": "http",
    "method": "POST",
    "bodyType": "json"
  },
  "output": {
    "type": "json",
    "example": {
      "limits": {
        "maxRows": 5000,
        "maxListed": 200,
        "maxColumns": 64,
        "maxCsvBytes": 262144,
        "maxDatasets": 10,
        "maxFindings": 500,
        "maxCategories": 1000,
        "maxKeyColumns": 4
      },
      "passed": false,
      "unique": false,
      "complete": true,
      "findings": [
        {
          "key": "grace@example.test",
          "row": 5,
          "code": "DUPLICATE_KEY",
          "detail": "grace@example.test appears 2 times, at rows 5, 6."
        },
        {
          "key": "ada@example.test",
          "row": 2,
          "code": "NEAR_DUPLICATE_KEY",
          "detail": "3 different keys become ada@example.test once lowercase and trim is applied, which a unique index would have accepted and is usually the same entity twice."
        }
      ],
      "row_count": 5,
      "duplicates": [
        {
          "key": "grace@example.test",
          "rows": [
            5,
            6
          ],
          "occurrences": 2
        }
      ],
      "request_id": "example-request",
      "service_id": "duplicate_key_audit",
      "assumptions": [
        "Keys are canonicalised exactly, so 1.0 and 1 are one key and a large identifier is compared as text rather than collapsed.",
        "A near duplicate is two different keys that become identical once the requested normalisation is applied. It is reported separately from an exact duplicate, because a unique index would have accepted ..."
      ],
      "limitations": [
        "Uniqueness within the dataset supplied. A duplicate against another dataset is not visible here.",
        "unique is true only when the dataset was fully read and no key repeated exactly or near-identically."
      ],
      "observed_at": "2026-10-02T00:00:00.000Z",
      "not_examined": [],
      "finding_count": 2,
      "empty_key_count": 0,
      "near_duplicates": [
        {
          "rows": [
            2,
            3,
            4
          ],
          "normalised_key": "ada@example.test",
          "distinct_exact_keys": 3
        }
      ],
      "service_version": "1.0.0",
      "findings_by_code": {
        "DUPLICATE_KEY": 1,
        "NEAR_DUPLICATE_KEY": 1
      },
      "distinct_key_count": 4,
      "supplied_row_count": 5,
      "duplicate_key_count": 1,
      "duplicate_row_count": 1,
      "near_duplicate_count": 1,
      "normalisation_applied": [
        "lowercase",
        "trim"
      ]
    }
  }
}