[yadavchiragg]

Problem: nothing checks that the demo workflows still generate a study after a change to mkconcore.py. A workflow for a language the generator doesn't support (for example demo/sampleJ.graphml, which uses Julia nodes) fails with Extension .jl is unsupported, and nobody sees it until a user builds that workflow.

Change: new tests/test_demo_workflows_generate.py runs mkconcore.py on every demo/*.graphml for posix, windows and docker. It checks that generation succeeds, that the expected scripts exist and are non-empty, and that src/ was created. The whole file runs in about 7 seconds.

sampleJ.graphml on posix and windows is marked xfail with a reason, because Julia nodes are not supported in local builds yet. The list is in KNOWN_UNSUPPORTED at the top of the file, so the entry can be deleted when that support lands.

Testing: all other cases pass. With the KNOWN_UNSUPPORTED entries removed, exactly the two Julia cases fail, which shows the test catches a real unsupported-language failure. ruff format --check and ruff check are clean.

[github-actions]

🎉 Welcome aboard, @yadavchiragg! Thank you for your first pull request in concore.

Please ensure that you are contributing to the dev branch.

Your contribution means a lot to us. We'll review it shortly.

Please ensure you have reviewed our:

• 📚 Project Documentation
• 📘 Contribution Guidelines
• 📜 Code of Conduct

If you have any questions, feel free to ask. Happy coding!