Deferred: cancel Cloudinary account

## Context

Media is served from Cloudflare R2 + Workers Images. Keep the Cloudinary account for a couple of weeks, then cancel when ready.

## Owner

Kent handles this manually; agents should not cancel or interact with the Cloudinary account.

## Acceptance criteria

- [ ] Kent cancels/closes the Cloudinary account or paid plan when ready.
- [ ] Spot-check production media after cancellation:
- [ ] A blog banner image
- [ ] `/media/...` asset URL
- [ ] The building-an-awesome-image-loading-experience post
- [ ] `/resources/og-image`

## Verification already completed

- 670 R2 masters checked against Cloudinary.
- 0 new originals need archiving.
- 14 originals already archived.
- 653 assets matched Cloudinary original sizes.
- 3 HEAD-unknown assets were checked by GET and exactly matched R2 sizes.

No code entry point is mentioned. Kent is responsible for manually cancelling the Cloudinary account or paid plan when ready; agents must not interact with the account. After cancellation, spot-check the listed production media, including a blog banner, a /media/... asset, the specified post, and /resources/og-image.

Written by the indexing model from the issue text.