fix(icom): standby is not a fault — the quiet recovery needs prior CI-V

A radio in standby is silent on CI-V by design; only the transport chats.
The quiet-recovery added for the mid-session deafness treated that silence
as the fault it usually is and tore the session down every 15 s — taking the
console and its ON button with it, so a radio that was off when OpsLog
started could never be turned on. The recovery now arms only once the
session has heard at least one CI-V payload.

internal/cat/icomnet.go

@@ -403,6 +403,12 @@ func (n *icomNet) civPump() {
 	var lastErr error
 	quietSaid := false
 	gaveUp := false
+	// sawData: this session has heard at least one CI-V payload. A radio in
+	// STANDBY is silent on CI-V by design — only the transport chats — and the
+	// quiet-recovery below must not treat that as a fault: it was tearing the
+	// session down every 15 s, and with it the console and its ON button, so a
+	// radio that was off when OpsLog started could never be turned on at all.
+	sawData := false
 	for {
 		select {
 		case <-n.done:
@@ -434,6 +440,7 @@ func (n *icomNet) civPump() {
 					debugLog.Printf("icom net: CI-V replies are back after %s", time.Since(lastData).Round(time.Second))
 					quietSaid, gaveUp = false, false
 				}
+				sawData = true
 				lastData = time.Now()
 				n.txAtData.Store(n.txCiv.Load())
 				n.trackRxSeq(icnLE.Uint16(buf[6:])) // note gaps for retransmit
@@ -468,7 +475,7 @@ func (n *icomNet) civPump() {
 				}
 			}
 		}
-		if !quietSaid && time.Since(lastData) > 10*time.Second {
+		if !quietSaid && sawData && time.Since(lastData) > 10*time.Second {
 			quietSaid = true
 			scopeAge := "never"
 			if !lastScope.IsZero() {