add simple workflow with LangGraph

[ks6088ts]

What this PR does / why we need it

add simple workflow with LangGraph

Which issue(s) this PR fixes:

Fixes #3

Does this introduce a breaking change?

[ ] Yes
[x] No

Pull Request Type

What kind of change does this Pull Request introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Documentation content changes
[ ] Other... Please describe:

How to Test

• Get the code

git clone [email protected]:ks6088ts-labs/sandbox-python.git
cd sandbox-python

• Test the code

make ci-test

What to Check

Verify that the following are valid

• ...

Additional Information