Track the declared JSON Schema dialect in the validator state and validate
dialect-sensitive constructs before applying a schema.
Recognize draft-04, draft-06, draft-07, 2019-09, and 2020-12, while preserving
the existing compatibility behavior for schemas without a $schema declaration.
Reject unknown dialects and known keywords or forms that do not belong to the
declared draft.
Implement draft-specific exclusive bound semantics, boolean-schema rules, and
array vocabulary differences. Document the behavior and add coverage for all
supported drafts.
The generated Gajumaru draft-04 configuration schema passes the new checks.
Ulf Wiger
25f81ae339