Particle Valid (Restriction) was keyed by type name, so an inline complexType
deriving by complexContent restriction was never checked against its base. Such
anonymous restrictions are now compiled and run through the same subset
algorithm as named types.
XSTS invalid-schemas-accepted 163 to 148, no other bucket moved.
A complexContent extension that explicitly states mixed must match its base
type's mixedness (cos-ct-extends.1.4.3.2.2.1): a mixed extension extends only a
mixed base, an element-only extension only an element-only base. An extension
that omits mixed inherits the base's setting and stays valid, so only an
explicit conflict is rejected (ctZ012b, which inherits, is not flagged).
XSTS invalid-schemas-accepted 197 to 194, no other bucket moved.
A complexContent extension that adds element content (a non-empty model
group) produces an element-only/mixed content type, so its base must have
complex or empty content, not simpleContent (cos-ct-extends.1.4.2.2). Such
schemas were accepted.
The check requires the extension to add actual element content (an element or
wildcard, not an empty group), so an attribute-only complexContent extension
of a simpleContent base stays valid (the complexContent-around-simpleContent
idiom, e.g. particlesZ031).
XSTS invalid-schemas-accepted 235 to 233, no other bucket moved.
Ship the OpenAPIKit-style validation layer (builtin rules, warnings channel,
Validator tiers, coverage gates) and wire XSD compile checks through it. Advance
#161 with chameleon include validation, multi-container reference resolution,
and include targetNamespace composition rules so merged schema sets compile
correctly when a schemaLoader is provided.
