chore: bump versions for release (2)

[polina-c]

Successor of #889, with version of a2ui_core changed to 0.0.1-dev002, that is one way to address the comment.

[gemini-code-assist]

Code Review

This pull request updates the genui and genui_a2a packages to version 0.9.0 across the repository, including several example applications. It also bumps the version of a2ui_core to 0.0.1-dev002 and removes it from the excluded packages list in the release tool. The changelogs for genui and genui_a2a have been updated to document new features, bug fixes, and breaking changes. A review comment suggests adding a trailing newline to the a2ui_core changelog to adhere to POSIX standards.

[gemini-code-assist]

The file is missing a trailing newline at the end. It is a best practice to ensure all text files end with a newline character to maintain compatibility with various POSIX tools and to avoid issues with version control diffs.

Suggested change

	- Initial version.
	- Initial version.

[jacobsimionato]

LGTM - thanks for coming up with a better approach here.

If I could turn back time, I think it might have been ideal to avoid adding a dependency from genui to a2ui_core before we were ready to release a2ui_core, seeing as now if we want to release genui we need to release a2ui_core. But I think we need to cross this bridge eventually, so I like your solution here of releasing a2ui_core, but with a version label that makes it clear that it's not ready for widespread use yet.

[polina-c]

LGTM - thanks for coming up with a better approach here.

If I could turn back time, I think it might have been ideal to avoid adding a dependency from genui to a2ui_core before we were ready to release a2ui_core, seeing as now if we want to release genui we need to release a2ui_core. But I think we need to cross this bridge eventually, so I like your solution here of releasing a2ui_core, but with a version label that makes it clear that it's not ready for widespread use yet.

I agree. Noted for future. It was me - I could not put Flutter adapter to the core library, because it is pure Dart. So I've put it to Flutter library genui, not thinking that it will block release.