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).
Close the remaining documented parity edges:
- Canonical XML 2.0 TrimTextNodes: an option that strips leading and trailing
whitespace from each text node (dropping all-whitespace nodes), exposed as
Options.canonical2.
- XML Catalog delegation and chaining: delegatePublic, delegateSystem,
delegateURI, and nextCatalog entries are parsed, and resolveSystem/
resolvePublic/resolveURI gain a loadingCatalog overload that follows the
longest matching delegate prefix and then each nextCatalog, with a
visited-set guard against cycles.
- XPath number formatting: the canonical string form now expands any exponent
in the shortest double rendering to a plain decimal, since XPath 1.0 forbids
scientific notation.
Closes#70
