feat: add API to download video and store in r2

[YangchenYe323]

No description provided.

[github-actions]

🚀 Preview Deployment

Your preview deployment is ready!

🔗 Preview URL: https://firefly-api-pr-4.your-subdomain.workers.dev

This preview will be updated automatically when you push new commits to this PR.

_{Deployed from commit: d5e0bb7}

[github-actions]

🚀 Preview Deployment

Your preview deployment is ready!

🔗 Preview URL: https://firefly-api-pr-4.eikasia30.workers.dev

This preview will be updated automatically when you push new commits to this PR.

_{Deployed from commit: 66c303a}

[github-actions]

🚀 Preview Deployment

Your preview deployment is ready!

🔗 Preview URL: https://firefly-api-pr-4.eikasia30.workers.dev

This preview will be updated automatically when you push new commits to this PR.

_{Deployed from commit: c59ce58}

[github-actions]

🚀 Preview Deployment

Your preview deployment is ready!

🔗 Preview URL: https://firefly-api-pr-4.eikasia30.workers.dev

This preview will be updated automatically when you push new commits to this PR.

_{Deployed from commit: 445130f}

[github-actions]

🚀 Preview Deployment

Your preview deployment is ready!

🔗 Preview URL: https://firefly-api-pr-4.eikasia30.workers.dev

This preview will be updated automatically when you push new commits to this PR.

_{Deployed from commit: 751a467}

[github-actions]

🚀 Preview Deployment

Your preview deployment is ready!

🔗 Preview URL: https://firefly-api-pr-4.eikasia30.workers.dev

This preview will be updated automatically when you push new commits to this PR.

_{Deployed from commit: 43a9931}

[YangchenYe323]

Somehow bilibili doesn't like the edge runtime. I couldn't get this to work. It has no problem with request coming from vercel nextjs though, so I guess I'd run this as a vercel cron instead.