feat: Yaesu control panel (meters, bands, DSP, TX), and drop a stale Flex hint

A console pane for the native Yaesu backend, in the same shape as the Icom and
Flex ones: S/PO/SWR meters, band and mode rows, AF/RF/squelch, AGC, the IPO/AMP1/
AMP2 front-end selector, ATT, NB, DNR + level, narrow filter, power in watts, mic
gain, VOX, split and ATU tune.

Three decisions worth keeping:

Panel reads are STAGGERED and live in their own file, away from ReadState. Meters
poll every cycle; settings only change when someone turns a knob, so they refresh
every 8th cycle and right after any set. Polling all of it every cycle would put
twenty queries a second on the serial link the frequency display shares.

Band buttons use the rig's own band memory (BS) rather than a frequency we pick,
so 20 m lands where the operator last was on 20 m — what the radio's own band
keys do.

A set is followed by a read-back, so the panel shows what the RIG ended up with,
not what we asked for; the two differ whenever a value is out of range or the
mode forbids the control. And a control the model lacks keeps its previous value
instead of dropping to zero, which reads as a setting that reset itself.

The S9 point of the S-meter scale is a hypothesis (the manual does not state it)
and is commented as such — one number to correct if reports come out an S unit
off, rather than a fudge spread through the RST helper.

Also removes the FlexRadio settings blurb, which explained the backend to
someone who had already chosen it.

changelog.json

@@ -3,6 +3,7 @@
     "version": "0.21.9",
     "date": "2026-07-28",
     "en": [
+      "Yaesu control panel: with the native Yaesu backend, a console pane gives S/PO/SWR meters, band and mode buttons, AF/RF/squelch, AGC, IPO-AMP1-AMP2, ATT, NB, DNR, narrow filter, power, mic gain, VOX, split and ATU tune. Enable it in Settings → Main view panes.",
       "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).",
       "Native Yaesu CAT: a new backend talks to an FTDX10/FTDX101 directly over its serial port, without OmniRig — frequency, mode, VFO A/B, split and PTT. Pick \"Yaesu (native CAT)\" in Settings → CAT. First release, feedback welcome.",
@@ -15,6 +16,7 @@
       "CQ and ITU zones you correct by hand in your profile stay corrected. They are derived from cty.dat, which gives the zones of the whole entity — in a country spanning several, the automatic value is wrong and it came back at every restart. They now only fill in when empty, and recompute when the callsign or grid changes."
     ],
     "fr": [
+      "Panneau de contrôle Yaesu : avec le backend Yaesu natif, un volet console offre les mesures S/PO/ROS, les boutons de bande et de mode, AF/RF/squelch, AGC, IPO-AMP1-AMP2, ATT, NB, DNR, filtre étroit, puissance, gain micro, VOX, split et accord d'antenne. À activer dans Réglages → Volets de la vue principale.",
       "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).",
       "CAT Yaesu natif : un nouveau backend dialogue directement avec un FTDX10/FTDX101 par son port série, sans OmniRig — fréquence, mode, VFO A/B, split et PTT. À choisir dans Réglages → CAT sous « Yaesu (CAT natif) ». Première version, retours bienvenus.",