Rewrite literal (|) and folded (>) block scalar content to YAML 1.2 section 8.1: preserve interior blank lines, apply 8.1.3 line folding (a single break between equally indented non-empty lines folds to a space, while blank lines and more-indented lines keep their breaks), preserve tabs in content (only block-indentation columns are stripped), and support the + keep chomping indicator alongside clip and strip.
The block scalar is now scanned as a single unit (header line plus all content lines) with indentation auto-detection in Scanner.BlockScalar.swift, mirroring the reference scanner, instead of being reassembled from a lossy per-line token array.
Flips 24 official YAML test suite cases to passing (220/402). Updates the gap manifest, vendored fixtures, count assertions, and the conformance roadmap.
Mihaela Mihaljevic
3db3e87d39