fix(dmr): block MOX and tune on receive mode

RadioController.pas

@@ -2145,6 +2145,13 @@ begin
     if S.Mode = MODE_DMR then Exit;
   end;
   if FTxSliceId = SliceId then Exit;
+  // Selecting main A while it is in DMR is allowed as an RX selection, but it
+  // cannot inherit an active carrier from a previously selected TX slice.
+  if (SliceId = 0) and (FMode = MODE_DMR) then
+  begin
+    if FTuning then SetTune(False)
+    else if FTransmitting then SetMOX(False);
+  end;
   FTxSliceId := SliceId;
   // Передающий тракт под режим нового источника (idle-канал, применится к PTT).
   if FWDSPReady and Assigned(FDSPEngine) then
@@ -3143,6 +3150,13 @@ end;
 procedure TRadioController.SetMode(M: Integer);
 begin
   FMode := M;
+  // Entering receive-only DMR on the selected main TX source immediately
+  // releases an existing carrier. SetTune(False) also releases MOX.
+  if ActiveTXMode = MODE_DMR then
+  begin
+    if FTuning then SetTune(False)
+    else if FTransmitting then SetMOX(False);
+  end;
   if Assigned(FDMRDec) then FDMRDec.SetEnabled(FMode = MODE_DMR);
   ApplyModeDefaults;                    // дефолтный фильтр/девиация под режим
   FBandCache[FCurrentBand].Mode := FMode;
@@ -4026,6 +4040,9 @@ procedure TRadioController.SetMOX(On_: Boolean);
 var
   WasTransmitting: Boolean;
 begin
+  // DMR support is receive-only. This guard also covers CAT, web and hardware
+  // PTT. A selected non-DMR TX slice remains valid while main A receives DMR.
+  if On_ and (ActiveTXMode = MODE_DMR) then Exit;
   // Safety: блокируем TX на бэндах с DoNotTx (Alex) и на RX-only трансвертере.
   if On_ and FDevConnected and (FCurrentXvtr < 0)
      and FAlexSettings.DoNotTx[EnsureRange(TxBandIdx, 0, 10)] then
@@ -4128,6 +4145,7 @@ end;
 procedure TRadioController.SetTune(On_: Boolean);
 begin
   if On_ = FTuning then Exit;
+  if On_ and (ActiveTXMode = MODE_DMR) then Exit;
   // Safety: те же блокировки, что и в SetMOX — TUN это TX через WDSP PostGen-тон,
   // он тоже должен молчать на бэндах с DoNotTx и на RX-only XVTR.
   if On_ and FDevConnected and (FCurrentXvtr < 0)