Currently, when a PR is submitted, only the tests in the a2a-java project get run:

https://github.com/a2aproject/a2a-java/blob/main/.github/workflows/build-and-test.yml

We should also run the a2a-tck to avoid regressions:

https://github.com/maeste/a2a-tck

We can use the 0.2.3 a2a-tck tag for now.

To run the TCK:

• We need to first start the Java system under test by going to the a2a-java/tck directory and running mvn quarkus:dev.
• Then, the TCK can be run using the instructions from its README (i.e., ./run_tck.py --sut-url http://localhost:9999 --category all --compliance-report report.json)

When we apply future spec updates, we can update the GitHub Action accordingly to checkout a newer a2a-tck spec tag.