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 complex type's simpleContent derivation can name another complex type with
simpleContent as its base. simpleContentType resolved a non-XSD, non-simpleType
base via context.simpleTypes only, so a complex-type base (absent from that map)
fell back to xs:string and left the content unconstrained: text invalid for the
real base type was accepted (baseTD00101, where Test restricts Test2 which extends
xs:int, yet "b" was accepted).
simpleContentBaseType now resolves the base to an XSD built-in, a named simple
type, or, when the base is a complex type with simpleContent, that type's own
resolved simple type by recursing through complexTypeNodes (cycle-guarded by a
visited set); the deriving node's facets are then applied over the resolved base's
facets. So Test resolves to int and non-int text is rejected, while a valid int
and the accumulated facets along the chain are honoured.
invalid-instances-accepted 39 to 37, no false positive (valid-instances-rejected
and valid-schemas-rejected held at 0), no other bucket moved. An adversarial
review exercised facet accumulation, named-simpleType bases in the chain,
multi-level and extension chains, and cycles, and found no over-rejection.
