feat(k3): a mode row on the Elecraft console — CW/USB/LSB/DATA/DATA-RTTY

The report: switching the K3 to a data mode 'does not work for FT8 — the K3
does not go into DATA'. The mode digit is only half the answer on that radio:
MD6 keeps whatever DT submode the previous session left, and with FSK D still
armed the rig keys FT8 with no rear-audio modulation.

The panel buttons say the whole thing: DATA is MD6+DT0 (DATA A, the soundcard
path), DATA RTTY is MD6+DT2 (FSK D). The DT submode is also read on the
settings beat — Elecraft only, a plain Kenwood would '?;' it — so the active
DATA button follows what the rig is actually in, front-panel changes included.
A dedicated SetKenwoodPanelMode rather than the logger's SetMode: a panel
button is the operator saying exactly what the rig should do, not an ADIF mode
to be mapped through preferences.

frontend/src/lib/i18n.tsx

@@ -130,6 +130,9 @@ const en: Dict = {
   'icmp.scopeNoStream': 'This radio does not send its scope over CI-V — its own screen still works.',
   'wk.catWarnTci': 'The CW keyer is set to the radio, but the CAT backend is "{backend}". Pick TCI in Settings → CAT, or another keying engine.',
   'wk.tciHint': "Keying goes through the radio's own macro keyer, over the link already open — no WinKeyer and no second serial port. The radio can stop a message but cannot un-type one, so there is no type-ahead correction here.",
+  'k3.modeData': 'DATA', 'k3.modeRtty': 'DATA RTTY',
+  'k3.modeDataHint': 'DATA A (MD6 + DT0) — the soundcard submode FT8/FT4/PSK modulate through',
+  'k3.modeRttyHint': 'FSK D (MD6 + DT2) — direct-keyed RTTY',
   'gen.iaruRegion': 'IARU region', 'gen.iaruHint': '(band plan drawn on the band maps)',
   'gen.iaruR1': 'Region 1 — Europe, Africa, Middle East', 'gen.iaruR2': 'Region 2 — Americas', 'gen.iaruR3': 'Region 3 — Asia-Pacific',
   'gen.miles': 'Distances in miles', 'gen.milesHint': '(instead of kilometres)',
@@ -633,6 +636,9 @@ const fr: Dict = {
   'icmp.scopeNoStream': "Cette radio n'envoie pas son scope en CI-V — son propre écran fonctionne toujours.",
   'wk.catWarnTci': "Le manipulateur CW est réglé sur la radio, mais le backend CAT est « {backend} ». Choisissez TCI dans Réglages → CAT, ou un autre moteur de manipulation.",
   'wk.tciHint': "La manipulation passe par le keyer à macros de la radio, sur la liaison déjà ouverte — ni WinKeyer ni second port série. La radio sait interrompre un message mais pas en effacer la fin, donc pas de correction en frappe anticipée ici.",
+  'k3.modeData': 'DATA', 'k3.modeRtty': 'DATA RTTY',
+  'k3.modeDataHint': 'DATA A (MD6 + DT0) — le sous-mode carte son par lequel FT8/FT4/PSK modulent',
+  'k3.modeRttyHint': 'FSK D (MD6 + DT2) — RTTY en manipulation directe',
   'gen.iaruRegion': 'Région IARU', 'gen.iaruHint': '(plan de bande dessiné sur les cartes de bande)',
   'gen.iaruR1': 'Région 1 — Europe, Afrique, Moyen-Orient', 'gen.iaruR2': 'Région 2 — Amériques', 'gen.iaruR3': 'Région 3 — Asie-Pacifique',
   'gen.miles': 'Distances en miles', 'gen.milesHint': '(au lieu des kilomètres)',