feat(ui): add /badge/compare/ endpoints

[OrbisK]

🔗 Linked issue

NA

🧭 Context

For the npmx Renovate preset, I wanted to add some e18e related badges. I think it would be useful to be able to identify e18e changes when reviewing a Renovate PR.

📚 Description

This PR adds /badge/compare/ endpoints. One for single package compare and one for cross package compare.

single package compare:

cross package compare:

I am not fully satisfied with the API. Perhaps it could be made a bit cleaner. Feedback welcome! (opening as draft for now)

This PR includes the changes of #2640

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Disclaimer: I have used claude for docs and to extract the shared utils for compare and normal badges

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Project	Deployment	Actions	Updated (UTC)
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npmx.dev	Ready	Preview, Comment	Apr 27, 2026 11:47am

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Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ All tests successful. No failed tests found.

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[OrbisK]

@43081j what do you think from an e18e perspective?

@serhalp any thoughts on the compare stuff?