refactor(cat): one DTR/RTS setting per backend, none shared

The 0.22.7/0.22.8 breakage came from a Xiegu-reported fault being fixed
inside the Yaesu and Kenwood backends. The lesson is structural: nothing
a backend does may be steered by another backend's report or another
backend's setting.

The lower-lines checkbox introduced for 0.22.9 was still one shared key
applied to both Yaesu and Kenwood — the same reflex in miniature. It is
now cat.yaesu.low_dtr_rts and cat.kenwood.low_dtr_rts, each checkbox in
its backend's own settings block, each wired only to its backend. The
shared key never shipped, so nothing needs migrating.

app.go

@@ -120,7 +120,12 @@ const (
 	keyCATKenwoodHost     = "cat.kenwood.host"    // Kenwood CAT over a network serial bridge (ser2net), "host:port"
 	keyCATKenwoodPort     = "cat.kenwood.port"    // Kenwood CAT serial port (TS-590/890/2000, Elecraft)
 	keyCATKenwoodBaud     = "cat.kenwood.baud"    // Kenwood CAT baud (TS-590 default 9600, TS-890 115200)
-	keyCATLowerLines      = "cat.serial.low_dtr_rts" // deassert DTR/RTS on connect (interfaces that read them as PTT)
+	// One key PER BACKEND, deliberately not shared. A Xiegu fix that reached
+	// into the Yaesu and Kenwood backends is what broke them in 0.22.7/0.22.8;
+	// the rule since is that nothing a backend does may be steered by another
+	// backend's setting.
+	keyCATYaesuLowLines   = "cat.yaesu.low_dtr_rts"   // deassert DTR/RTS on connect
+	keyCATKenwoodLowLines = "cat.kenwood.low_dtr_rts" // deassert DTR/RTS on connect
 	keyCATIcomPort        = "cat.icom.port"           // Icom USB CI-V serial port (e.g. COM5)
 	keyCATIcomBaud        = "cat.icom.baud"           // Icom CI-V baud (default 115200)
 	keyCATIcomAddr        = "cat.icom.addr"           // Icom CI-V address, decimal (IC-7610 = 152 / 0x98)
@@ -379,10 +384,11 @@ type CATSettings struct {
 	// adapter). NOT the radio’s own RJ45, which speaks Kenwood’s KNS/ARCP.
 	KenwoodPort string `json:"kenwood_port"` // Kenwood CAT serial port (TS-590/890/2000, Elecraft)
 	KenwoodBaud int    `json:"kenwood_baud"` // Kenwood CAT baud (TS-590 default 9600)
-	// LowerLines deasserts DTR and RTS after opening a serial CAT port, for
+	// Per-backend: deassert DTR and RTS after opening the CAT port, for
 	// interfaces that read either line as PTT. Off by default: lowering them
 	// stops some USB-serial interfaces transmitting at all.
-	LowerLines     bool   `json:"lower_lines"`
+	YaesuLowLines   bool   `json:"yaesu_low_lines"`
+	KenwoodLowLines bool   `json:"kenwood_low_lines"`
 	IcomPort        string `json:"icom_port"`       // Icom USB CI-V serial port (e.g. COM5)
 	IcomBaud        int    `json:"icom_baud"`       // Icom CI-V baud (default 115200)
 	IcomAddr        int    `json:"icom_addr"`       // Icom CI-V address, decimal (IC-7610 = 152)
@@ -6824,7 +6830,7 @@ func (a *App) GetCATSettings() (CATSettings, error) {
 	if a.settings == nil {
 		return CATSettings{Backend: "omnirig", OmniRigNum: 1, PollMs: 250}, fmt.Errorf("db not initialized")
 	}
-	m, err := a.settings.GetMany(a.ctx, keyCATEnabled, keyCATBackend, keyCATOmniRigNum, keyCATOmniRigVFO, keyCATFlexHost, keyCATFlexPort, keyCATFlexSpots, keyCATFlexDecodeSpots, keyCATFlexDecodeSecs, keyCATXieguPort, keyCATXieguBaud, keyCATXieguAddr, keyCATXieguPTTLine, keyCATYaesuPort, keyCATYaesuBaud, keyCATKenwoodPort, keyCATKenwoodBaud, keyCATKenwoodHost, keyCATLowerLines, keyCATIcomPort, keyCATIcomBaud, keyCATIcomAddr, keyCATIcomNetHost, keyCATIcomNetUser, keyCATIcomNetPass, keyCATIcomNetAudio, keyCATTCIHost, keyCATTCIPort, keyCATTCISpots, keyCATPollMs, keyCATDelayMs, keyCATDigitalDefault, keyCATShareEnabled, keyCATSharePort)
+	m, err := a.settings.GetMany(a.ctx, keyCATEnabled, keyCATBackend, keyCATOmniRigNum, keyCATOmniRigVFO, keyCATFlexHost, keyCATFlexPort, keyCATFlexSpots, keyCATFlexDecodeSpots, keyCATFlexDecodeSecs, keyCATXieguPort, keyCATXieguBaud, keyCATXieguAddr, keyCATXieguPTTLine, keyCATYaesuPort, keyCATYaesuBaud, keyCATKenwoodPort, keyCATKenwoodBaud, keyCATKenwoodHost, keyCATYaesuLowLines, keyCATKenwoodLowLines, keyCATIcomPort, keyCATIcomBaud, keyCATIcomAddr, keyCATIcomNetHost, keyCATIcomNetUser, keyCATIcomNetPass, keyCATIcomNetAudio, keyCATTCIHost, keyCATTCIPort, keyCATTCISpots, keyCATPollMs, keyCATDelayMs, keyCATDigitalDefault, keyCATShareEnabled, keyCATSharePort)
 	if err != nil {
 		return CATSettings{}, err
 	}
@@ -6845,7 +6851,8 @@ func (a *App) GetCATSettings() (CATSettings, error) {
 		KenwoodPort:     m[keyCATKenwoodPort],
 		KenwoodHost:     m[keyCATKenwoodHost],
 		KenwoodBaud:     9600,
-		LowerLines:      m[keyCATLowerLines] == "1",
+		YaesuLowLines:   m[keyCATYaesuLowLines] == "1",
+		KenwoodLowLines: m[keyCATKenwoodLowLines] == "1",
 		IcomPort:        m[keyCATIcomPort],
 		IcomBaud:        115200,
 		IcomAddr:        0x98, // IC-7610 default
@@ -6981,9 +6988,11 @@ func (a *App) SaveCATSettings(s CATSettings) error {
 	if s.DigitalDefault == "" {
 		s.DigitalDefault = "FT8"
 	}
-	lowerLines := "0"
+	b01 := func(v bool) string {
-	if s.LowerLines {
+		if v {
-		lowerLines = "1"
+			return "1"
+		}
+		return "0"
 	}
 	shareEnabled := "0"
 	if s.ShareEnabled {
@@ -7008,7 +7017,8 @@ func (a *App) SaveCATSettings(s CATSettings) error {
 		keyCATKenwoodPort:     strings.TrimSpace(s.KenwoodPort),
 		keyCATKenwoodHost:     strings.TrimSpace(s.KenwoodHost),
 		keyCATKenwoodBaud:     strconv.Itoa(s.KenwoodBaud),
-		keyCATLowerLines:      lowerLines,
+		keyCATYaesuLowLines:   b01(s.YaesuLowLines),
+		keyCATKenwoodLowLines: b01(s.KenwoodLowLines),
 		keyCATIcomPort:        strings.TrimSpace(s.IcomPort),
 		keyCATIcomBaud:        strconv.Itoa(s.IcomBaud),
 		keyCATIcomAddr:        strconv.Itoa(s.IcomAddr),
@@ -12839,7 +12849,7 @@ func (a *App) reloadCAT() {
 		// (a rig file that hides the VFO, a Freq property meaning A on one model
 		// and B on another); talking to the radio directly removes it.
 		yz := cat.NewYaesu(s.YaesuPort, s.YaesuBaud, s.DigitalDefault)
-		yz.SetLowerLines(s.LowerLines)
+		yz.SetLowerLines(s.YaesuLowLines)
 		a.cat.Start(yz)
 	case "kenwood":
 		// Native Kenwood CAT — TS-590/890/990/2000 and everything that speaks the
@@ -12853,7 +12863,7 @@ func (a *App) reloadCAT() {
 			a.cat.Start(cat.NewKenwoodTCP(h, s.DigitalDefault))
 		} else {
 			kw := cat.NewKenwood(s.KenwoodPort, s.KenwoodBaud, s.DigitalDefault)
-			kw.SetLowerLines(s.LowerLines)
+			kw.SetLowerLines(s.KenwoodLowLines)
 			a.cat.Start(kw)
 		}
 	case "icom":

frontend/src/components/SettingsModal.tsx

@@ -1136,7 +1136,7 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
   const [modeDraft, setModeDraft] = useState('');
   const [catCfg, setCatCfg] = useState<CATSettings>({
     enabled: false, backend: 'omnirig', omnirig_rig: 1, omnirig_vfo: '', flex_host: '', flex_port: 4992, flex_spots: false, flex_decode_spots: false, flex_decode_secs: 120,
-    yaesu_port: '', yaesu_baud: 38400, lower_lines: false, kenwood_port: '', kenwood_baud: 9600, kenwood_host: '', xiegu_port: '', xiegu_baud: 19200, xiegu_addr: 0x70, xiegu_ptt_line: '',
+    yaesu_port: '', yaesu_baud: 38400, yaesu_low_lines: false, kenwood_low_lines: false, kenwood_port: '', kenwood_baud: 9600, kenwood_host: '', xiegu_port: '', xiegu_baud: 19200, xiegu_addr: 0x70, xiegu_ptt_line: '',
     icom_port: '', icom_baud: 115200, icom_addr: 0x98, icom_net_host: '', icom_net_user: '', icom_net_pass: '', icom_net_audio: false,
     tci_host: '', tci_port: 40001, tci_spots: false, poll_ms: 250, delay_ms: 0,
     digital_default: 'FT8', share_enabled: false, share_port: 4532,
@@ -2582,7 +2582,7 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
               </div>
               <div className="space-y-1">
                 <label className="flex items-center gap-2 text-xs cursor-pointer">
-                  <Checkbox checked={!!catCfg.lower_lines} onCheckedChange={(c) => setCatCfg((s) => ({ ...s, lower_lines: !!c }))} />
+                  <Checkbox checked={!!catCfg.yaesu_low_lines} onCheckedChange={(c) => setCatCfg((s) => ({ ...s, yaesu_low_lines: !!c }))} />
                   {t('cat.lowerLines')}
                 </label>
                 <span className="text-xs text-muted-foreground">{t('cat.lowerLinesHint')}</span>
@@ -2636,7 +2636,7 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
               </div>
               <div className="space-y-1">
                 <label className="flex items-center gap-2 text-xs cursor-pointer">
-                  <Checkbox checked={!!catCfg.lower_lines} onCheckedChange={(c) => setCatCfg((s) => ({ ...s, lower_lines: !!c }))} />
+                  <Checkbox checked={!!catCfg.kenwood_low_lines} onCheckedChange={(c) => setCatCfg((s) => ({ ...s, kenwood_low_lines: !!c }))} />
                   {t('cat.lowerLines')}
                 </label>
                 <span className="text-xs text-muted-foreground">{t('cat.lowerLinesHint')}</span>

frontend/wailsjs/go/models.ts

@@ -1924,7 +1924,8 @@ export namespace main {
 	    kenwood_host: string;
 	    kenwood_port: string;
 	    kenwood_baud: number;
-	    lower_lines: boolean;
+	    yaesu_low_lines: boolean;
+	    kenwood_low_lines: boolean;
 	    icom_port: string;
 	    icom_baud: number;
 	    icom_addr: number;
@@ -1965,7 +1966,8 @@ export namespace main {
 	        this.kenwood_host = source["kenwood_host"];
 	        this.kenwood_port = source["kenwood_port"];
 	        this.kenwood_baud = source["kenwood_baud"];
-	        this.lower_lines = source["lower_lines"];
+	        this.yaesu_low_lines = source["yaesu_low_lines"];
+	        this.kenwood_low_lines = source["kenwood_low_lines"];
 	        this.icom_port = source["icom_port"];
 	        this.icom_baud = source["icom_baud"];
 	        this.icom_addr = source["icom_addr"];