E2B fixes a bug that silently corrupted file uploads

E2B shipped 2.37.0 on July 31, fixing a bug that made sandbox uploads silently store the string "[object Blob]" instead of the file itself.

The two failure modes weren't equal. A bad Request crashed loudly with "Failed to parse URL from [object Request]," an error you'd catch in minutes. A bad Blob didn't crash at all. It just wrote the wrong bytes and let the upload finish, the kind of failure that clears code review and shows up as a support ticket weeks later.

The cause: the old code used instanceof to detect Request, Blob and ReadableStream objects, which breaks the moment a library installs its own version of those globals.

@hono/node-server ships its own Request. Remix's installGlobals() swaps in Request, Blob and File. web-streams-polyfill replaces ReadableStream. Any of those in a user's stack and the checks stopped matching.

The fix checks object shape instead of instanceof, so a Request or Blob built by any of those libraries gets recognized correctly, per the changelog. The same release adds sandbox images for Fedora, Alpine and Arch Linux.

What makes the instanceof bug worth flagging is that it looks correct in review. It's standard JavaScript, it works in every test that doesn't happen to import Remix or hono. It only breaks in front of a real user's dependency tree, and when it breaks, it doesn't tell you. Worth grepping your own upload code for "instanceof Blob" before someone else finds it.