postany: hand an agent a file, get a live URL

Field notes

The service accepts an entry file plus additional paths through multipart form data or JSON, then returns a public subdomain and an update token for later PUT requests. Its temporary links serve for seven days, continue through a 48-hour grace period, and answer 410 after expiry unless restored before purge. The documented limits are 100 files per publish, 10 MB total, 2 MB per file, and 10 retained versions. Unchanged files are omitted from later uploads.