fix(cat): stop deasserting DTR/RTS on Kenwood and Yaesu

d4bfd30 fixed a Xiegu G90 behind a DE-19 that keyed on connect, and I
applied the same line-lowering to Kenwood and Yaesu with no evidence that
either needed it. It silenced them: many USB-serial interfaces will not
transmit with RTS low — hardware flow control, or an output stage the
line enables. A TS-990 on COM3 opened cleanly and answered nothing, which
reached us as "CAT stopped working after the update".

Xiegu keeps the behaviour: that is where the fault was reported, and that
backend now has an explicit setting for which line keys the rig. The CI-V
backend keeps its own, which predates all of this.

Kenwood also distinguishes a silent port from one sending data that never
answers, and quotes what arrived — "the rig is not answering" sent an
operator checking the power switch on a radio whose frames were visibly
on the wire.

changelog.json

@@ -5,12 +5,16 @@
     "en": [
       "Main tab: drag the divider between the two panes to resize them. The setting is remembered and travels with the data folder; double-click the divider to even them out.",
       "Kenwood: bytes arriving glued to the previous answer are no longer discarded, and the link starts from a clean buffer — a rig whose replies ran together could end up one answer behind and never report connected.",
-      "The CAT log line now carries the error explaining a disconnection."
+      "The CAT log line now carries the error explaining a disconnection.",
+      "Kenwood and Yaesu CAT connect again: 0.22.7 lowered the DTR and RTS lines on those ports, which stops many USB-serial interfaces from transmitting. Only Xiegu, where the problem was reported, still does it.",
+      "Kenwood: a port that opens but sends nothing is now reported differently from one sending data that does not answer, and the error quotes what arrived."
     ],
     "fr": [
       "Onglet Principal : faites glisser le séparateur entre les deux volets pour les redimensionner. Le réglage est mémorisé et suit le dossier de données ; double-clic pour les égaliser.",
       "Kenwood : les octets reçus collés à la réponse précédente ne sont plus jetés, et la liaison démarre sur un tampon vide — une radio dont les réponses s’enchaînent pouvait rester une réponse en retard et ne jamais apparaître connectée.",
-      "La ligne de journal CAT indique désormais l’erreur expliquant une déconnexion."
+      "La ligne de journal CAT indique désormais l’erreur expliquant une déconnexion.",
+      "Le CAT Kenwood et Yaesu se connecte de nouveau : la 0.22.7 abaissait les lignes DTR et RTS sur ces ports, ce qui empêche beaucoup d’interfaces USB-série d’émettre. Seul Xiegu, où le problème avait été signalé, le fait encore.",
+      "Kenwood : un port qui s’ouvre sans rien émettre est désormais distingué d’un port qui émet sans répondre, et l’erreur cite ce qui est arrivé."
     ]
   },
   {