Keep the connection state in the status bar on /window (closes #225)

/window set the status bar to [connected] whatever the connection
state, and Alt and a digit runs /window. Before /connect, both made
the status bar say [connected] while the client had no session.

/window now reads the connection state with the nick and shows
[connected] only while the client is connected, [disconnected]
otherwise. TestWindowConnectionState types /window 0 and presses
Alt and 0, connected and not, and checks the status bar.

Model: opus-5-5

internal/cli/app.go

@@ -626,8 +626,14 @@ func (a *App) cmdWindow(args string) {
 
 	a.mu.Lock()
 	nick := a.nick
+	connected := a.connected
 	a.mu.Unlock()
 
+	connStatus := "disconnected"
+	if connected {
+		connStatus = "connected"
+	}
+
 	// Read the name before switching. A message from the server can
 	// add a buffer at any time, but only at the end, so bufIndex
 	// still names this buffer when SwitchBuffer runs.
@@ -641,14 +647,14 @@ func (a *App) cmdWindow(args string) {
 			a.mu.Unlock()
 
 			a.ui.SetStatus(
-				nick, name, "connected",
+				nick, name, connStatus,
 			)
 		} else {
 			a.mu.Lock()
 			a.target = ""
 			a.mu.Unlock()
 
-			a.ui.SetStatus(nick, "", "connected")
+			a.ui.SetStatus(nick, "", connStatus)
 		}
 	}
 }