Magic Wormhole: get things from one computer to another, safely

Magic-wormhole is really intended to help with the first-step "introduction" phase of a tool like that: start with two humans that can yell a codephase at each other, and finish with two computers that have a secure encrypted connection. Once you've got that connection, you can send whatever you want through it.

The `wormhole send` tool is a good demonstration of what you can do with that API, and a convenient tool in its own right, but wasn't designed to be the end-all-be-all of the file transfer universe, nor to be a building block for other tools layered on top.

The application you describe would be pretty cool (the UI might look more like dropping a file into a Slack DM chat window). But I'd recommend against using automated calls to `wormhole send` to accomplish it: you'd be cutting against the grain, and adding load to the mailbox server that everyone else uses. Instead, build a separate app or daemon, which can use the magic-wormhole API to perform just the introduction step. You'd push the "invite a peer" button on your app, it would display a wormhole code, you speak that to your pal, they push the "accept invitation" button on their app, type in the code, and then the two apps exchange keys/addresses. All subsequent transfers use those established keys, and don't need to use the wormhole code again. You should never need to perform a wormhole dance more than once per peer.