Proxy drops image/jpeg upload bodies because binary content-type allowlist only includes image/png

## Summary Nango Proxy appears to drop request bodies for direct binary uploads with `Content-Type: image/jpeg`. We hit this while uploading receipt attachments to Xero through Nango Proxy. The same flow works for PDFs, but JPEG uploads reach Xero as an empty file. ## Observed behavior Client sends a `PUT` request through Nango Proxy with: - `Content-Type: image/jpeg` - nonzero `Content-Length` - binary JPEG body Nango forwards the request to Xero, but Xero receives the attachment as empty and returns: ```text The file to be attached must have some content. ``` Xero's error payload showed `ContentLength: 0`. ## Expected behavior Nango Proxy should preserve and forward the binary request body for `image/jpeg`, the same way it does for `application/pdf` and `application/octet-stream`. ## Suspected root cause In current `master`, public proxy body parsing depends on: ```ts bodyParser.raw({ type: (req) => isBinaryContentType(req.headers['content-type']), limit: bodyLimit }) ``` `isBinaryContentType()` uses this allowlist: ```ts const BINARY_CONTENT_TYPES = [ 'image/png', 'video/', 'audio/', 'application/', 'text/', 'font/', 'model/', 'message/', 'chemical/', 'x-world/', 'application/octet-stream' ]; ``` Because this includes `image/png` but not `image/jpeg` or broad `image/`, JPEG request bodies are not raw-parsed and the proxy forwards an empty body. ## Suggested fix Change the image MIME allowlist from: ```ts 'image/png' ``` to: ```ts 'image/' ``` or explicitly add common image upload types such as: ```ts 'image/jpeg', 'image/jpg', 'image/webp', 'image/heic' ``` A regression test for `Content-Type: image/jpeg` proxy uploads would be useful. ## Related PRs This looks related to, but not fully covered by: - #2708 - #3551 - #2643 #3551 added more binary upload support, but current `master` still appears to miss `image/jpeg`.