Converts a Node.js Buffer into a DOM-compatible BlobPart.
Recent TypeScript DOM typings require BlobPart byte views to be backed by a
concrete ArrayBuffer, while Buffer is typed as ArrayBufferLike. Returning
a plain Uint8Array avoids that mismatch for multipart image uploads.
Converts a Node.js
Bufferinto a DOM-compatibleBlobPart.Recent TypeScript DOM typings require
BlobPartbyte views to be backed by a concreteArrayBuffer, whileBufferis typed asArrayBufferLike. Returning a plainUint8Arrayavoids that mismatch for multipart image uploads.