Function start_on_server 

pub(crate) fn start_on_server(
    qt: &CxxQtThread<Sioul>,
    shared: &Arc<Shared>,
    account: String,
    place: String,
    passphrase: String,
    again: String,
)

Starts sharing through a folder of an account’s files that Sioul keeps in step itself (remote::MIRROR): joined when another device shares through it already (its seal, the passphrase chosen there), else made there and sealed (the passphrase typed twice). Off the window’s thread: the result comes through share_started (“” when it did, else why not).