Single (') and double (") quoted multi-line scalars now apply YAML 1.2 flow folding (sections 6.5, 7.3.1, 7.3.2): trailing whitespace before a break is stripped, leading whitespace on continuation lines is stripped, a single break between non-empty lines folds to one space, and N consecutive breaks yield N-1 literal line feeds (first and last lines keep their own leading/trailing spaces as content). A double-quoted backslash at end of line suppresses the break entirely.
Complete the double-quoted escape set: add \xXX and \UXXXXXXXX hex escapes plus the previously missing \0 \a \v \e, literal backslash-space, and named breaks \N \_ \L \P (existing \uXXXX surrogate-pair handling kept). The folding state machine mirrors scanner.c yaml_parser_scan_flow_scalar; implemented in Sources/Parsing/Scalar.swift.
Flips 30 official YAML test suite cases to passing (250/402). Updates the gap manifest, fixtures, count assertions, and roadmap.
Mihaela Mihaljevic
88b67ff0b2