Validate CSV schema and convert ETL rows to typed JSON
https://agent-evidence-extractor.defcronyke.workers.dev/v1/csv-import-jsonOverview
Pre-import CSV cleanup, validation, and conversion for ETL/database loads. Optional exact, case-sensitive header_aliases map vendor headers to declared canonical columns before cleanup, validation, and conversion; optional ordered per-column trim, whitespace-collapse, case, and control-character rules then run before required-header, type, unique-key, and value-rule checks. Passing rows are converted into JSON. Set coerce_types=true for native nu