fix: accept Hamlib's VFO-prefixed commands — JTDX could not set the frequency

MSHV worked immediately, JTDX answered "Hamlib error: Invalid parameter while
setting frequency". The two use different Hamlib dialects: MSHV sends
"F 14074000", JTDX names the target first — "F VFOA 14074000". The VFO name
landed in the slot the frequency was read from, the parse failed, and we returned
RPRT -1, which is exactly the error JTDX reported.

A leading VFO name is now stripped from every command's arguments. It costs
nothing: OpsLog follows the rig's own VFO selection, so the name carries no
information we act on — but refusing it locked out a whole family of clients.
Both dialects are covered by a test, the plain one included, since this is an
addition and must not become a swap.

A rejected frequency is also logged with the raw line now. The client only shows
"Invalid parameter", which says nothing about what it actually sent — that is
why this took a screenshot to diagnose rather than a log.

changelog.json

@@ -3,7 +3,7 @@
     "version": "0.21.9",
     "date": "2026-07-28",
     "en": [
-      "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.",
+      "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.",
       "Changing band from OpsLog now updates the displayed frequency straight away. The rig moved, but its answer arrived inside the short grace window that protects what you are typing and was discarded — so the frequency stayed on the old band until you nudged the VFO.",
       "Bulk edit can now set the contacted station gridsquare, so a batch of QSOs imported without a locator can be corrected in one go.",
@@ -14,7 +14,7 @@
       "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": [
-      "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.",
+      "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.",
       "Changer de bande depuis OpsLog met désormais la fréquence affichée à jour immédiatement. La radio se déplaçait bien, mais sa réponse arrivait pendant le court délai qui protège votre saisie et était ignorée — la fréquence restait donc sur l'ancienne bande jusqu'à ce qu'on touche le VFO.",
       "L'édition groupée peut désormais définir le locator de la station contactée : un lot de QSO importés sans locator se corrige en une fois.",