Uploads a local file to R2 via a streaming multipart upload, for
server-side producers (e.g. the YouTube import/trim job) that already
have a finished file on local disk and are not going through the
browser presigned-URL flow.
Parameters
localFilePath: string
Absolute path to the file to upload.
key: string
Destination R2 object key.
contentType: string
MIME type to set on the object.
Returns Promise<number>
The final object size in bytes, for downstream size bookkeeping.
Uploads a local file to R2 via a streaming multipart upload, for server-side producers (e.g. the YouTube import/trim job) that already have a finished file on local disk and are not going through the browser presigned-URL flow.