when you get write-access to a directory, it comes with a "suggested added convergence secret"

[zooko]

I was thinking the other day that I share writecaps to directories among multiple computers and I didn't think to replicate the added convergence secret to all of those computers, so I may have missed some opportunities for convergent upload.

It would be cool if a directory had a "suggested added convergence secret" stored in it, encrypted under the directory's writecap. Then whenever I authorized another one of my computers to write to that directory and uploaded a file into the directory, the node would fetch the added convergence secret from the directory, decrypt it, and use that for files that it was uploading with the intent to subsequently link them into that directory.