feat: CW through the Yaesu keyer — fifth CW engine

The radio has a keyer and a command to feed it (KY), so an FTDX10 needs no
WinKeyer and no second cable, exactly as the Icom CI-V and Flex CWX engines
already do. The rig keys with its own timing, which is why the spacing is right
where a PC keying a line through USB latency drifts.

Text is filtered to what the keyer can actually send: an unsupported byte does
not produce an error on a Yaesu, it can abort the whole buffer, so the rest of a
macro would vanish silently. It is then fed in 24-character pieces, waiting for
room between them — the rig DROPS what does not fit, again with no error, so a
contest CQ would lose its tail.

STOP is the honest gap. Yaesu documents no buffer-clear, so it drops the
transmitter (TX0) instead: nothing queued reaches the air, which is what Escape
means to an operator. It deliberately does NOT send "KY0;" — a plausible-looking
clear that the rig would read as the CHARACTER zero and transmit.

A test caught a real one on the way: tabs and newlines were dropped as
"unsupported", gluing the words either side together, so a macro written on two
lines went out as CQCQ. Whitespace now becomes a word gap before filtering.

Settings warn when the Yaesu keyer is selected without the Yaesu CAT backend —
otherwise it simply never keys, with nothing on screen saying why.

Send path follows the CAT reference and how Hamlib drives these rigs; NOT yet
verified on the air.

changelog.json

@@ -4,6 +4,7 @@
     "date": "2026-07-28",
     "en": [
       "Yaesu control panel: with the native Yaesu backend, a console tab and Main-view pane give S/PO/SWR meters, band and mode buttons, AF/RF/squelch, AGC, IPO-AMP1-AMP2, a 6/12/18 dB attenuator, NB, DNR, narrow filter, power, mic gain, VOX, split and ATU tune. CW, RTTY, DIGI and PSK show their sideband — click an active button again to switch it. Pressing SPLIT places the transmit VFO relative to where you are listening — up 1 kHz on CW and data, up 5 kHz on phone — and shows the transmit frequency; +1k and +5k buttons cover the rest.",
+      "CW through the Yaesu keyer: a fifth CW engine sends your macros with the radio own keyer (CAT \"KY\") — no WinKeyer, no second cable. Pick \"Yaesu (rig keyer)\" in Settings → CW keyer, with the Yaesu CAT backend active.",
       "The Yaesu console follows the mode: in CW the microphone gain and VOX disappear and a CW card takes their place with keyer speed, break-in and ZIN (zero-in).",
       "Native Xiegu CAT (G90, X6100, X6200, X5105): a new backend talks CI-V straight to the radio — frequency, mode, split and PTT. Pick \"Xiegu (native CI-V)\" in Settings → CAT. Untested on a radio so far, feedback welcome.",
       "CAT sharing: OpsLog can now serve its rig connection to other programs (Settings → CAT → Share CAT). WSJT-X, JTDX, MSHV or Log4OM connect with rig model \"Hamlib NET rigctl\" at 127.0.0.1:4532 — needed because a native CAT backend holds the radio serial port on its own. Works with every backend, and with both Hamlib command dialects (JTDX names the VFO, MSHV does not).",
@@ -18,6 +19,7 @@
     ],
     "fr": [
       "Panneau de contrôle Yaesu : avec le backend Yaesu natif, un onglet console et un volet de la vue principale offrent les mesures S/PO/ROS, les boutons de bande et de mode, AF/RF/squelch, AGC, IPO-AMP1-AMP2, un atténuateur 6/12/18 dB, NB, DNR, filtre étroit, puissance, gain micro, VOX, split et accord d'antenne. CW, RTTY, DIGI et PSK affichent leur bande latérale — recliquez sur le bouton actif pour en changer. Appuyer sur SPLIT place le VFO d'émission par rapport à votre écoute — +1 kHz en CW et numérique, +5 kHz en phonie — et affiche la fréquence d'émission ; les boutons +1k et +5k couvrent le reste.",
+      "CW par le keyer Yaesu : un cinquième moteur CW envoie vos macros avec le keyer de la radio (CAT « KY ») — sans WinKeyer ni second câble. À choisir dans Réglages → Keyer CW sous « Yaesu (keyer de la radio) », avec le backend CAT Yaesu actif.",
       "La console Yaesu suit le mode : en CW, le gain micro et le VOX disparaissent au profit d'une carte CW avec la vitesse du manipulateur, le break-in et ZIN (zéro-in).",
       "CAT Xiegu natif (G90, X6100, X6200, X5105) : un nouveau backend dialogue en CI-V directement avec la radio — fréquence, mode, split et PTT. À choisir dans Réglages → CAT sous « Xiegu (CI-V natif) ». Pas encore testé sur une radio, retours bienvenus.",
       "Partage du CAT : OpsLog peut désormais servir sa liaison radio aux autres logiciels (Réglages → CAT → Partager le CAT). WSJT-X, JTDX, MSHV ou Log4OM s'y connectent avec le modèle « Hamlib NET rigctl » sur 127.0.0.1:4532 — nécessaire car un backend CAT natif occupe seul le port série. Fonctionne avec tous les backends, et avec les deux dialectes Hamlib (JTDX nomme le VFO, MSHV non).",