#3553 fix: Resolve `$ref`s in `additionalProperties` Pull request opened by edgarrmondragon See • #3552 for the full context. Summary by Sourcery Resolve JSON Schema $ref references across all nested schema keywords, including additionalProperties, while expanding coverage of the reference resolver. Bug Fixes: • Ensure $ref references nested inside additionalProperties are correctly resolved when building schemas. • Prevent missed reference resolution in other JSON Schema container keywords by centralizing recursive traversal logic. Tests: • Add a schema resolution test covering $ref usage inside additionalProperties to verify correct reference expansion. meltano/sdk