remove CW decoder (audio->text) entirely; fix CWX macro not stopping on call typing

- Removes the RX-audio CW decoder: deletes app_cw.go + internal/cwdecode, the
  cwDecoder/cwPitchHz/cwMu/cwStop App fields, and all frontend state/effects, the
  header Ear button, the Tools menu item and the decoded-text strip. The CW
  KEYER (WinKeyer/Icom/Flex) is untouched.
- Fix: typing a callsign while a macro is keying now aborts the CURRENT engine
  (Flex CWX / Icom / WinKeyer) on the first character, not just WinKeyer during
  an auto-call loop — via a shared stopKeyerTx() helper.

frontend/wailsjs/go/main/App.js

@@ -102,10 +102,6 @@ export function BulkUpdateQSL(arg1, arg2) {
   return window['go']['main']['App']['BulkUpdateQSL'](arg1, arg2);
 }
 
-export function CWDecoderRunning() {
-  return window['go']['main']['App']['CWDecoderRunning']();
-}
-
 export function ChatAvailable() {
   return window['go']['main']['App']['ChatAvailable']();
 }
@@ -606,10 +602,6 @@ export function GetCATState() {
   return window['go']['main']['App']['GetCATState']();
 }
 
-export function GetCWDecoderPitch() {
-  return window['go']['main']['App']['GetCWDecoderPitch']();
-}
-
 export function GetCatalogCodes() {
   return window['go']['main']['App']['GetCatalogCodes']();
 }
@@ -1558,10 +1550,6 @@ export function SetCATMode(arg1) {
   return window['go']['main']['App']['SetCATMode'](arg1);
 }
 
-export function SetCWDecoderPitch(arg1) {
-  return window['go']['main']['App']['SetCWDecoderPitch'](arg1);
-}
-
 export function SetClublogCtyEnabled(arg1) {
   return window['go']['main']['App']['SetClublogCtyEnabled'](arg1);
 }
@@ -1598,18 +1586,10 @@ export function SetUltrabeamDirection(arg1) {
   return window['go']['main']['App']['SetUltrabeamDirection'](arg1);
 }
 
-export function StartCWDecoder() {
-  return window['go']['main']['App']['StartCWDecoder']();
-}
-
 export function StationSetRelay(arg1, arg2, arg3) {
   return window['go']['main']['App']['StationSetRelay'](arg1, arg2, arg3);
 }
 
-export function StopCWDecoder() {
-  return window['go']['main']['App']['StopCWDecoder']();
-}
-
 export function SwitchCATRig(arg1) {
   return window['go']['main']['App']['SwitchCATRig'](arg1);
 }