Convert CSV to JSON or flat JSON to CSV, preserving row order

Convert one pasted CSV table to JSON, or one flat JSON array to CSV. Return the converted data inside a Markdown report, preserving row order, duplicates and whitespace. CSV values remain strings, including leading zeros. Blank physical CSV records become rows of empty strings. JSON-to-CSV uses columns in first-appearance order; missing keys and null become empty cells, and numbers/booleans become text. JSON-to-CSV requires at least one named column. No cleaning, enrichment or external calls. CSV formula-like text remains literal; import as text in spreadsheets. Up to 128 KiB of UTF-8 input, 2000 rows and 50 columns. CSV needs unique non-empty headers and consistent row widths; JSON must be an array of flat objects with finite scalar values. Two in-scope correction rounds. AI-assisted service operated by Ilya using deterministic Python. Submit only non-sensitive data.