Group @testable imports at the bottom, per public/rules-swift's swiftformat. A
behavior-preserving import-ordering reformat across 252 files (mostly tests).
--trailingclosures was deliberately not adopted (cosmetic, and swiftformat flags
it as caution-worthy).
disable-output-escaping on xsl:value-of and xsl:text (sentinel-marked
raw text, unescaped after serialization; string extraction from a
fragment drops the markers per 16.4), the html default method for a
null-namespace html root (16.1), the spec-default XML declaration for
the xml method, META Content-Type injection into head (16.2),
case-insensitive raw-text and void element classes, and HTML 4.01
Latin-1 named entities on html output. Whitespace-only stripping now
means XML whitespace, so NBSP-only text survives. Conf comparison
treats tag-adjacent whitespace as layout outside the canonical path.
Xalan baseline 371 -> 352 (output 49 -> 30).
Add the PureXML.HTML namespace: a lenient tokenizer for tag-soup input
(case-insensitive tags; quoted, unquoted, and boolean attributes; comments;
doctype; character references), a tree builder handling void elements,
optional end tags (li, p, table rows and cells), raw-text elements (script,
style), and unmatched end tags, and a serializer that writes void elements
unclosed and raw-text content unescaped.
Closes#36Closes#37Closes#38Closes#39Closes#20
