feat(tci): key CW through the radio's own macro keyer

The sixth CW engine, and the one the TCI backend was left without. A SunSDR
keys from the WebSocket that already carries the CAT: no WinKeyer, no second
serial port, nothing to wire.

    CW_MACROS:0,<text>;     send
    CW_MACROS_SPEED:<wpm>;  speed
    CW_MACROS_STOP;         abort

Confirmed against the TCI command table in ars-ka0s/eesdr-tci — the source that
settled SPOT. CW_MACROS rather than TCI 2.0's CW_MSG: it exists from 1.6, and
OpsLog resolves its own variables, so the before/after callsign fields have
nothing to carry.

Commas and semicolons are stripped before sending. They are the protocol's own
separators: a comma would become another argument, a semicolon would end the
command with the message half keyed and the rest parsed as a command.

Only the MACRO speed is set, not the paddle keyer's — an operator who set their
paddle to 28 wpm did not ask for it to change because a macro went out at 25.
And there is no backspace: TCI can stop a message but cannot un-type one, so the
type-ahead correction the Flex engine offers is absent rather than faked.

frontend/src/lib/i18n.tsx

@@ -128,6 +128,8 @@ const en: Dict = {
   'mx.tipDxConf': 'Entity confirmed (other callsign)', 'mx.tipDxWork': 'Entity worked (other callsign)',
   'mx.tipNone': 'Never worked', 'mx.tipClick': 'click to list the QSOs',
   '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.",
   'gen.miles': 'Distances in miles', 'gen.milesHint': '(instead of kilometres)',
   'qslm.qrzTitle': 'Open this callsign on QRZ.com',
   'qslm.lotwDetail': 'QSL details',
@@ -626,6 +628,8 @@ const fr: Dict = {
   'mx.tipDxConf': 'Entité confirmée (autre indicatif)', 'mx.tipDxWork': 'Entité contactée (autre indicatif)',
   'mx.tipNone': 'Jamais contacté', 'mx.tipClick': 'cliquer pour lister les QSO',
   '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.",
   'gen.miles': 'Distances en miles', 'gen.milesHint': '(au lieu des kilomètres)',
   'qslm.qrzTitle': 'Ouvrir cet indicatif sur QRZ.com',
   'qslm.lotwDetail': 'Détails QSL',