12f99702b4
Whether a program is on the other end is the one fact worth a permanent place on screen, because every command in the client is a lie without it. Until now it was discovered by something failing, which is the worst moment to learn it. Three states, not two. `off' is never connected; `lost' is a daemon that has gone away, which is the ordinary case rather than an error — `flan dev' ends when its program does, and a program under development exits all the time. So `lost' is reconnected from, on the socket it was on, the next time anything is sent. The reconnect is strictly *before* a send and never after one. A connection that dies mid-request might have died after the daemon took the request and ran it; resending would install a definition twice, or evaluate a side-effecting expression twice. That case now reports what happened and says it was not resent, rather than silently doing it again. A socket that is not there is refused by name with the path, and a deliberate `flan-disconnect' forgets the socket, so the next command says "not connected" instead of quietly reopening what was just closed.