feat: Add Cloudflare AI Provider

[jacobdr]

Closes #647

Cloudflare Workers AI provider implementation

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This is a work in progress I wanted to put up for initial feedback. I still need to test it a bunch more locally and update the docs as well.

[jacobdr]

@typpo Anything else major besides docs that you think might be missing, assuming a correct implementation on my part of the CF API calls?

[jacobdr]

Note to self, look at https://github.com/promptfoo/promptfoo/pull/711/files for inspiration on examples + docs

[jacobdr]

@typpo the line changes related to formatting are due to VS code auto-format. I tried to remove then by running npm run format but that command generated a MASSIVE diff so I think you might want to consider enforcing the styling in CI in a separate effort

[typpo]

Nice change! This looks pretty much ready to go. Hopefully @CamdenClark can find the time to verify this weekend, otherwise I'll figure out how to get myself set up on Cloudflare AI :)

[CamdenClark]

Nice change! This looks pretty much ready to go. Hopefully @CamdenClark can find the time to verify this weekend, otherwise I'll figure out how to get myself set up on Cloudflare AI :)

I got to it! It works on my machine!

Thanks for taking this up, I got super distracted and forgot to do it 😓

In the future it would be cool to get LoRA support but that's not necessary to merge in my opinion.

Feel free to tag me on a non-draft PR if you want another review.

[CamdenClark]

one other thing you might want to know -- I had to build promptfoo on a new machine with node 22 and I got some weird C++ errors with better-sqlite. Might want to put a note recommending node 20. (Unrelated to this PR specifically)

[jacobdr]

@CamdenClark thanks for testing for me....

@typpo im working now on the docco after fixing the failing tests today. Would you mind please re-triggering the CI test workflow so that I can verify that worked? Assuming thats green, and once I push one more commit for the docs and a few more examples, then this should be good to go (though I'll do a final rebase against master before un-drafting it)

[jacobdr]

@typpo this is now done and awaiting final review + green CI

[typpo]

This change looks excellent! Nice work! Just waiting for green CI and will land it ✨

[typpo]

🎉 Amazing work @jacobdr and thanks @CamdenClark for helping too!