Note Mark: Path traversal via unsanitized book/note slug in migrate export (sibling of GHSA-g49p)

Summary Note Mark validates book and note slug values with the OpenAPI/huma tag pattern:"a-z0-9-+". huma compiles this with regexp.MustCompiles.Pattern and tests it with patternRe.MatchStringstr, an UNANCHORED match. Because the pattern is not anchored ^...$, any string that merely CONTAINS one...