fix: IC-7610 VFO A over OmniRig + faster Icom LAN reconnect

OmniRig: on the IC-7610 the generic Freq property reports the wrong VFO (its
Main/Sub model confuses the stock ini), so OpsLog showed VFO B. Detect the rig
by RigType and, in simplex, read VFO A explicitly — matching Log4OM. Only the
7610 is affected; other rigs keep using the generic Freq.

Icom network: when the rig tears the session down (control/CI-V 0x05) OpsLog
only logged it and kept the half-dead link until the 6 s liveness timeout
expired. Mark the link dead on 0x05 so Alive() fails on the next poll and the
manager reconnects cleanly right away.

internal/cat/omnirig.go

@@ -32,6 +32,7 @@ type OmniRig struct {
 	omnirig *ole.IDispatch
 	rig     *ole.IDispatch
 	lastSig string // last logged Split/VFO signature — only log on change
+	rigType string // OmniRig's RigType string (the .ini title), e.g. "IC-7610"
 
 	// lastSetFreq is the frequency most recently COMMANDED via SetFrequency.
 	// SetMode uses it to pick USB vs LSB for "SSB" instead of reading OmniRig's
@@ -80,11 +81,20 @@ func (o *OmniRig) Connect() error {
 	o.rig = rigVar.ToIDispatch()
 
 	if rt, err := oleutil.GetProperty(o.rig, "RigType"); err == nil {
-		debugLog.Printf("OmniRig connected to Rig%d type=%q", o.RigNum, rt.ToString())
+		o.rigType = rt.ToString()
+		debugLog.Printf("OmniRig connected to Rig%d type=%q", o.RigNum, o.rigType)
 	}
 	return nil
 }
 
+// isIC7610 reports whether the connected rig is an IC-7610. OmniRig's generic
+// Freq property reads the wrong VFO on the 7610 (its Main/Sub model confuses the
+// stock ini), so we read VFO A explicitly for it instead — matching what Log4OM
+// shows.
+func (o *OmniRig) isIC7610() bool {
+	return strings.Contains(strings.ToUpper(o.rigType), "7610")
+}
+
 func (o *OmniRig) Disconnect() {
 	if o.rig != nil {
 		o.rig.Release()
@@ -199,6 +209,12 @@ func (o *OmniRig) ReadState() (RigState, error) {
 		s.Split = false
 		s.RxFreqHz = 0
 		s.FreqHz = freqMain
+		// IC-7610 quirk: OmniRig's generic Freq reports VFO B (its Main/Sub model
+		// confuses the stock ini), so OpsLog showed the wrong VFO. Read VFO A
+		// explicitly for the 7610 — what the operator actually wants to see.
+		if o.isIC7610() && freqA != 0 {
+			s.FreqHz = freqA
+		}
 		if s.FreqHz == 0 {
 			if s.Vfo == "B" || s.Vfo == "BB" {
 				s.FreqHz = freqB