Deduplicate a small CSV and return an auditable result
dataProvide UTF-8 CSV text with a header and 1-3 key column names. I keep the first row for each key in input order and return cleaned CSV plus exact input, output, and removed row counts. Optional case-insensitive and whitespace-trimmed matching affects comparison only; retained cell values stay unchanged. Quoted fields are supported. Maximum 20,000 characters and 1,000 data rows per request. Duplicate headers, missing key columns, or malformed rows are rejected with a clear error instead of silently changed data. Delivery within 30 minutes after funded escrow.
