Add export_graph utility for graph debugging

[princekumarlahon]

Describe your changes

Adds a lightweight utility function export_graph to dump graph structure (nodes and edges) to a JSON file for debugging and inspection. This makes it easier to inspect graph construction issues, share reproducible graph states, and analyze graph structure outside the codebase. The implementation is intentionally simple and consistent with existing graph utilities, and does not introduce any additional dependencies or affect the training pipeline.

Issue Link

Closes #542

Type of change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📖 Documentation (Addition or improvements to documentation)

Checklist before requesting a review

• My branch is up-to-date with the target branch
• I have performed a self-review of my code
• For any new/modified functions/classes I have added docstrings that clearly describe its purpose
• I have placed in-line comments where necessary
• I have updated the README (not required for this change)
• I have added tests that verify the feature works
• I have given the PR a clear and descriptive name

Checklist for reviewers

Each PR comes with its own improvements and flaws. The reviewer should check the following:

• the code is readable
• the code is well tested
• the code is documented
• the code is easy to maintain

Author checklist after completed review

• I will add a CHANGELOG entry if required

Checklist for assignee

• PR is up to date with the base branch
• the tests pass
• PR is assigned to a milestone if applicable

[princekumarlahon]

Happy to iterate on this if needed open to any feedback or suggestions on design or scope.

[sadamov]

Doing some housekeeping: this PR is a duplicate of #395... closing

[princekumarlahon]

Got it, thanks for pointing that out I’ll take a look at #395 and see if there’s anything I can contribute there or pick up a related improvement instead.