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": "",