feat: add YAML download support for SDG analysis output

[adarsh-7-satyam]

Summary

The tool currently only supports downloading the SDG analysis output as a JSON file (unsdg.json). However, the DMP 2026 expected outcome explicitly states:

"Anyone should be able to access the tool and get the json or yaml output file from the tool."

YAML is currently missing as a download format.

Current Behavior

The download section in frontend/components/results.tsx only has a single button that generates and downloads unsdg.json. There is no YAML download option anywhere in the frontend.

Expected Behavior

Users should be able to download the same SDG analysis data as a unsdg.yaml file, giving them flexibility in how they use the output — especially useful for contributors testing against the DPG registry who may prefer YAML for metadata workflows.

Impact

• Directly addresses the DMP 2026 expected outcome which mentions YAML output
• No backend changes required — this is a pure frontend addition
• No new dependencies needed — YAML conversion can be handled with a lightweight helper function
• Zero regression risk to existing JSON download functionality

References

• DMP 2026 expected outcome: "get the json or yaml output file from the tool"
• frontend/components/results.tsx — current download implementation (JSON only)
• Issue [DMP 2026]: Minimum Viable Product (MVP) requirements #8 — DMP 2026 MVP requirements

[adarsh-7-satyam]

Hi @Sunilshah-7 and @david-lippert,

I wanted to flag this issue as I believe it is a small but important gap in the current tool.

While going through the entire codebase in preparation for DMP 2026, I noticed that the README and the DMP 2026 expected outcome both explicitly mention that users should be able to get "the json or yaml output file from the tool." However, looking at frontend/components/results.tsx, the download section only has a single button that generates unsdg.json — there is no YAML support anywhere in the frontend.

This means the tool is currently not fully delivering on what is promised in the expected outcome. Contributors testing against the DPG registry may also prefer YAML for their metadata workflows, so having both formats available would make the tool more flexible and complete.

I have already opened PR #54 which addresses this by:

• Adding a lightweight convertToYaml() helper function with no new dependencies
• Adding a handleDownloadYaml() function that generates unsdg.yaml
• Adding a "Download as YAML" button alongside the existing "Download as JSON" button

The fix is purely frontend, touches only results.tsx, and has zero regression risk to the existing JSON download functionality.

Would love your feedback on this whenever you get a chance!