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).
A constraining facet may not be applied where a simpleContent restriction's base
chain resolves to xs:anySimpleType, the ur simple type, which carries no
constraining facets (XSD Part 2 3.2.1); stZ010 (a complex type extending
xs:anySimpleType, restricted by another that adds minLength) is now rejected.
The base chain is followed through local complex types' own simpleContent bases;
it stops at any other built-in, a simple type, or an external/unresolved base, and
a restriction supplying its own nested simpleType base is skipped (the facet
applies to that), so a facet on a string-, int-, or other real-typed simpleContent
stays accepted.
XSTS invalid-schemas-accepted 49 -> 48, no false positive (valid-schemas-rejected
and valid-instances-rejected held at 0; an adversarial critic probed 12 valid
schemas across every resolver branch and confirmed FP-safety), no other bucket
moved.
