Swift: Ensure A2UICommonSchema and schema JSON stay in sync

From this [PR comment](https://github.com/a2ui-project/a2ui/pull/1994/changes/BASE..d4e4f99ef04e85cc5dac1ecbfe27d9a72f72d046#r3600247088), it would be great if there was a way to generate the inline Swift representation of the core A2UI JSON schema so that they stay in sync. Ideally this could be done with code generation, but at the very least, there should be a way to enforce that they are the same in CI.

Look at the A2UICommonSchema Swift file and the core JSON schema definition. Investigate existing CI workflows and code generation tools used in the project. Determine how to compare the two representations or generate one from the other, and add a check or generation step to the CI pipeline.

由索引模型根据 Issue 内容生成。