IN: CSV header, quoted comma, quoted newline, source order, row limit 2, UTF-8 byte limit 48
VALID: part-001.csv and part-002.csv each repeat the header, keep two complete records and measure 48 bytes
INVALID: oversized complete record, row-limit breach, byte-limit breach => reject without truncation or partial delivery
OUT: character-count substitute, broken quoted record, upload, storage, network, automatic delivery and real customer data
ROLLBACK: remove only V09 pages, fixtures, sitemap entries and focused checks