Verify that quoted excerpts actually appear in their source texts, tolerant of PDF line-wraps, whitespace collapse, Unicode ligatures/accents, SGML entities, and mid-quote elision. Invoke before treating any direct quotation as citation-safe -- e.g. before a manuscript goes to a reviewer, before a quote ledger is marked verified, or whenever a mechanical substring check reports a quote as missing from its source and that result needs to be trusted or distrusted.
