fix(cw): activate the Kenwood/Elecraft keyer engine when selected

The frontend engine loader had no "kenwood" case, so a saved engine of
"kenwood" fell through to the WinKeyer default — the Kenwood/Elecraft
CW-over-CAT engine never ran even though the setting showed it selected.

Also clarify the Kenwood data-mode comment: there is no single mode digit
right for both a K3 (DATA=MD6) and a TS-590SG (MD6=FSK), so data stays on
USB as the safe common base; a rig-specific DATA mode is a follow-up.

changelog.json

@@ -1,4 +1,14 @@
 [
+  {
+    "version": "0.23.4",
+    "date": "",
+    "en": [
+      "CW keyer (Kenwood/Elecraft): choosing the Kenwood/Elecraft engine now actually switches to it. A bug left the keyer on WinKeyer even though the setting showed Kenwood/Elecraft, so its CW-over-CAT never ran."
+    ],
+    "fr": [
+      "Keyer CW (Kenwood/Elecraft) : choisir le moteur Kenwood/Elecraft y bascule désormais réellement. Un bug laissait le keyer sur WinKeyer alors que le réglage affichait Kenwood/Elecraft, son CW-sur-CAT ne démarrait donc jamais."
+    ]
+  },
   {
     "version": "0.23.3",
     "date": "",

frontend/src/App.tsx

@@ -2706,8 +2706,9 @@ export default function App() {
         s.engine === 'icom' ? 'icom'
           : s.engine === 'flex' ? 'flex'
             : s.engine === 'yaesu' ? 'yaesu'
-              : s.engine === 'serial' ? 'serial'
-                : 'winkeyer');
+              : s.engine === 'kenwood' ? 'kenwood'
+                : s.engine === 'serial' ? 'serial'
+                  : 'winkeyer');
     } catch { /* keyer not configured */ }
   }, []);
 

internal/cat/kenwood.go

@@ -551,11 +551,12 @@ func kenwoodModeDigit(mode string, hz int64) byte {
 		}
 		return '2'
 	}
-	// Any other digital mode (FT8, PSK, JT…) rides the DATA input, and by universal
-	// convention that is ALWAYS the UPPER sideband, on every band. The SSB rule
-	// (LSB below 10 MHz) must NOT be applied here: doing so put a 40/80 m data spot
-	// on LSB, which an Elecraft K3 shows as "DATA REV" — the reversed sideband.
-	// (RTTY/FSK is handled above as its own FSK mode, so it isn't affected.)
+	// Any other digital mode (FT8, PSK, JT…) → USB on every band. There is NO single
+	// mode digit that is right for both families: a K3 wants DATA (MD6), a TS-590SG
+	// wants USB-DATA (MD2 + its DATA modifier), and MD6 on the TS-590SG is FSK/RTTY
+	// — wrong for FT8. USB is the safe common base (the reversed-sideband "DATA REV"
+	// only came from the old LSB-below-10-MHz rule). A rig-specific DATA mode is a
+	// follow-up that needs the model, not a blind default.
 	return '2'
 }