feat(omnirig): say which of its two CW bits means CW on this rig

Reported on an IC-7610 shared through OmniRig: clicking a CW spot put
the radio in CW-R every time, and the only way out was to edit the
OmniRig rig file by hand.

OmniRig's model has two CW modes, PM_CW_U and PM_CW_L, and nothing in it
says which one an .ini calls plain CW. Icom rig files disagree with each
other — on some PM_CW_U is CI-V mode 0x03 (CW), on others 0x07 (CW-R) —
so asking for "CW" is a question with two right answers and OpsLog was
only ever giving one of them.

Settings ▸ CAT ▸ OmniRig now carries the answer for THIS rig, and it is
pushed to a radio that is already connected rather than waiting for a
reconnect: which bit a mode maps to is not worth dropping the link, and
with it WSJT-X's rigctl session. Same shape as the Yaesu RTTY sideband,
for the same reason.

Nothing changes for anyone whose rig file already agrees with us.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

internal/cat/cat.go

@@ -1145,6 +1145,23 @@ func (m *Manager) YaesuDo(fn func(YaesuController) error) error {
 	})
 }
 
+// OmniRigController is the handful of OmniRig preferences that can be changed
+// without dropping the rig link.
+type OmniRigController interface {
+	SetCWLower(bool) // which of OmniRig's two CW bits means plain CW
+}
+
+// OmniRigDo dispatches an OmniRig preference onto the CAT goroutine.
+func (m *Manager) OmniRigDo(fn func(OmniRigController) error) error {
+	return m.exec(func(b Backend) error {
+		oc, ok := b.(OmniRigController)
+		if !ok {
+			return fmt.Errorf("active CAT backend is not OmniRig")
+		}
+		return fn(oc)
+	})
+}
+
 // KenwoodController is the Kenwood/Elecraft CW-over-CAT capability (the KY keyer),
 // so a K3 can key CW through its single CAT link instead of a second COM port.
 type KenwoodController interface {

internal/cat/flex.go

@@ -71,10 +71,10 @@ type Flex struct {
 	// Satellite pair: slice A is the downlink, slice B the uplink. -1 when not
 	// armed. satCreatedTX marks an uplink slice OpsLog opened, and is the only
 	// one it will close again.
-	satOn        bool
-	satRX        int
-	satTX        int
-	satCreatedTX bool
+	satOn           bool
+	satRX           int
+	satTX           int
+	satCreatedTX    bool
 	spotCall        map[int]string // spot index → callsign (to fill the call on a panadapter click)
 	spotMode        map[int]string // spot index → ADIF mode, so a click can also set the slice mode (SmartSDR tunes the spot's freq but not its mode)
 	spotFreq        map[int]int64  // spot index → Hz, so a click can report where it was (the trigger message carries only the index)

internal/cat/omnirig.go

@@ -36,6 +36,14 @@ type OmniRig struct {
 	// on the main VFO) and read B — the frequency "never followed the knob",
 	// while it was following the other one all along.
 	ForceVFO string
+	// CWLower sends PM_CW_L rather than PM_CW_U when asked for CW.
+	//
+	// OmniRig has two CW modes and nothing says which one an .ini file calls
+	// plain CW. Icom rig files disagree: on some PM_CW_U is CI-V mode 0x03 (CW),
+	// on others it is 0x07 (CW-R). An operator clicking a CW spot on an IC-7610
+	// landed in CW-R every time and had to edit the rig file to get out of it.
+	// This is the setting that means he does not have to.
+	CWLower bool
 
 	omnirig *ole.IDispatch
 	rig     *ole.IDispatch
@@ -76,7 +84,7 @@ type OmniRig struct {
 // NewOmniRig creates a non-connected backend. Call Connect before use.
 // NewOmniRig builds the backend. forceVFO is "" to follow whatever the rig file
 // reports, or "A"/"B" to override it — see the ForceVFO field.
-func NewOmniRig(rigNum int, forceVFO string) *OmniRig {
+func NewOmniRig(rigNum int, forceVFO string, cwLower bool) *OmniRig {
 	if rigNum < 1 || rigNum > 2 {
 		rigNum = 1
 	}
@@ -84,7 +92,7 @@ func NewOmniRig(rigNum int, forceVFO string) *OmniRig {
 	if v != "A" && v != "B" {
 		v = ""
 	}
-	return &OmniRig{RigNum: rigNum, ForceVFO: v}
+	return &OmniRig{RigNum: rigNum, ForceVFO: v, CWLower: cwLower}
 }
 
 func (o *OmniRig) Name() string { return "omnirig" }
@@ -602,6 +610,13 @@ func (o *OmniRig) SetFrequency(hz int64) error {
 	return nil
 }
 
+// SetCWLower chooses which of OmniRig's two CW bits means plain CW.
+//
+// Applied to the RUNNING backend, because the CAT link does not depend on it:
+// dropping the rig — and with it WSJT-X's rigctl session — to change which bit
+// a mode maps to would cost far more than it fixes.
+func (o *OmniRig) SetCWLower(on bool) { o.CWLower = on }
+
 // SetMode maps an ADIF mode to the OmniRig PM_* bit and pushes it to the rig.
 // For SSB, the USB/LSB side is chosen from the rig's current frequency
 // following worldwide convention (LSB below 14 MHz, USB above).
@@ -625,7 +640,13 @@ func (o *OmniRig) SetMode(mode string) error {
 	)
 	switch strings.ToUpper(strings.TrimSpace(mode)) {
 	case "CW":
-		bit, bitName = pmCWU, "PM_CW_U"
+		// Which bit means plain CW is a property of the RIG FILE, not of CW —
+		// see the CWLower field.
+		if o.CWLower {
+			bit, bitName = pmCWL, "PM_CW_L"
+		} else {
+			bit, bitName = pmCWU, "PM_CW_U"
+		}
 	case "SSB":
 		// Decide USB vs LSB from the frequency. Prefer the freq we just COMMANDED
 		// (a clicked spot sets freq then mode ~150ms later): OmniRig's Freq