I ran into another issue while using PropelAuth's Cloudflare SDK on celld 0.4.1. `atob()` rejects Base64 strings when the trailing `=` padding is omitted, which causes JOSE to fail when decoding JWT signatures.

For now I'm patching the sdk, but apparently that padding is [optional for `atob()`](https://infra.spec.whatwg.org/#forgiving-base64-decode). Here is a minimal repro:

```js atob("YQ=="); // "a" atob("YQ"); // Should also return "a", but throws InvalidCharacterError ```

Here is a patch with a fix:

[0001-Implement-forgiving-Base64-decoding-for-atob.patch](https://github.com/user-attachments/files/32133749/0001-Implement-forgiving-Base64-decoding-for-atob.patch)

My industrious little bot found a few more edge cases, but I will submit separate issues for those to keep the patches focused.