Phase 3 (batch 12): consolidate VFO B tuning into controller command

The "set VFO B" engine block was duplicated inline across three tune paths
(DoSpectrumClick, DoSpectrumDrag, FreqDispBChanged), each subtly different
(drag had no band-detect/ruler; click had no drive recalc).

- TRadioController.SetVfoB(Hz): always stores FVfoB; when B is the active
  VFO, retunes the receiver (DDC=VFO B, no CTUN, shift 0), HF band-detects
  (FCurrentBand + drive recalc -> Changed(rfBand)) and pushes to the radio;
  when B is inactive (split, listening on A) it only stores the freq for TX.
  Fires Changed(rfVfoB).
- OnControllerState(rfVfoB): renders FreqDispB and, when B active, the
  spectrum/ruler (deferred via FSpectrumDirty, matching the rfVfoA path).

The three call sites collapse to a single FController.SetVfoB(...) each;
FreqDispBChanged is now a one-liner. Behavior unified: click/FreqDispB drop
from sync DrawSpectrum to deferred (consistent with VFO A click-to-tune,
imperceptible); drag gains band-detect + ruler refresh; click gains drive
recalc on band change. Net -23 lines.

Left inline (not identical): DoWidebandClick VFO B (extra XVTR clamp +
wideband-specific render) and SyncWebFreq (uses SetRunAndFreq, the web/run
network path, not UpdateState+SendFullHP). Builds clean, links.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

MainForm.pas

@@ -1410,6 +1410,18 @@ begin
             if PbWaterfall <> nil then PbWaterfall.Invalidate;
           end;
         end;
+      rfVfoB:
+        begin
+          FreqDispB.Frequency := Round(FController.FVfoB);
+          if FController.FActiveVfo = 1 then
+          begin
+            FSpecView.InvalidateRulerCache;
+            SyncSpecViewFreq;
+            FSpectrumDirty := True;
+            PbSpectrum.Invalidate;
+            if PbRuler <> nil then PbRuler.Invalidate;
+          end;
+        end;
       rfBand:
         for i := 0 to BAND_COUNT - 1 do
           StyleButton(BtnBand[i], i = FController.FCurrentBand);
@@ -4485,35 +4497,10 @@ begin
 end;
 
 procedure TMainForm.FreqDispBChanged(Sender: TObject; NewFreq: Int64);
-var
-  BandIdx: Integer;
 begin
-  FController.FVfoB := NewFreq;
+  // Движок (сохранение B, перестройка при активном B, диапазон, сеть) — в
-  if FController.FActiveVfo = 1 then
+  // контроллере; рендер — OnControllerState(rfVfoB).
-  begin
+  FController.SetVfoB(NewFreq);
-    // VFO-B активен: перестраиваем приёмник
-    FController.FCenterFreq := FController.FVfoB;
-    if FController.FWDSPReady then FController.FDSPEngine.SetShift(0.0);
-    if FController.FNetwork.Connected and FController.FNetwork.Running then
-    begin
-      FController.FNetwork.UpdateState(XvtrTranslate(FController.FCenterFreq), XvtrTranslate(ActiveTXFreqHz), FController.FDriveLevel, FController.FTransmitting, True, True);
-      FController.FNetwork.SendFullHP;
-    end;
-    // Обновляем диапазон
-    BandIdx := FreqToBandIdx(FController.FVfoB);
-    if (BandIdx >= 0) and (BandIdx <> FController.FCurrentBand) then
-    begin
-      StyleButton(BtnBand[FController.FCurrentBand], False);
-      FController.FCurrentBand := BandIdx;
-      StyleButton(BtnBand[FController.FCurrentBand], True);
-      FController.FDriveLevel := CalcDriveByte;
-    end;
-    FSpecView.InvalidateRulerCache;
-    SyncSpecViewFreq;
-    FSpecView.DrawSpectrum;
-    PbSpectrum.Invalidate;
-    if PbRuler <> nil then PbRuler.Invalidate;
-  end;
 end;
 
 // ---------------------------------------------------------------------------
@@ -4773,7 +4760,6 @@ procedure TMainForm.DoSpectrumClick(PixelX: Integer; PanelWidth: Integer);
 var
   ClickFreq: Int64;
   StepHz:    Int64;
-  BandIdx:   Integer;
 begin
   if PanelWidth <= 0 then Exit;
   if (FController.FMode = MODE_FM) and FController.FFMStepOn then
@@ -4785,29 +4771,7 @@ begin
   if FController.FActiveVfo = 0 then
     ApplyVfoA(ClickFreq)
   else
-  begin
+    FController.SetVfoB(ClickFreq);  // движок + рендер через OnControllerState(rfVfoB)
-    FController.FVfoB := ClickFreq;
-    FreqDispB.Frequency := Round(FController.FVfoB);
-    FController.FCenterFreq := ClickFreq;
-    if FController.FWDSPReady then FController.FDSPEngine.SetShift(0.0);
-    if FController.FNetwork.Connected and FController.FNetwork.Running then
-    begin
-      FController.FNetwork.UpdateState(XvtrTranslate(FController.FCenterFreq), XvtrTranslate(ActiveTXFreqHz), FController.FDriveLevel, FController.FTransmitting, True, True);
-      FController.FNetwork.SendFullHP;
-    end;
-    BandIdx := FreqToBandIdx(FController.FVfoB);
-    if (BandIdx >= 0) and (BandIdx <> FController.FCurrentBand) then
-    begin
-      StyleButton(BtnBand[FController.FCurrentBand], False);
-      FController.FCurrentBand := BandIdx;
-      StyleButton(BtnBand[FController.FCurrentBand], True);
-    end;
-    FSpecView.InvalidateRulerCache;
-    SyncSpecViewFreq;
-    FSpecView.DrawSpectrum;
-    PbSpectrum.Invalidate;
-    if PbRuler <> nil then PbRuler.Invalidate;
-  end;
 end;
 
 procedure TMainForm.DoWidebandClick(PixelX: Integer; PanelWidth: Integer);
@@ -4931,18 +4895,7 @@ begin
     if FController.FActiveVfo = 0 then
       ApplyVfoA(Round(FSpecDragFreq - dFreq))
     else
-    begin
+      FController.SetVfoB(FSpecDragFreq - dFreq);  // движок + рендер (rfVfoB)
-      FController.FVfoB := FSpecDragFreq - dFreq;
-      FreqDispB.Frequency := Round(FController.FVfoB);
-      FController.FCenterFreq := FController.FVfoB;
-      if FController.FWDSPReady then FController.FDSPEngine.SetShift(0.0);
-      if FController.FNetwork.Connected and FController.FNetwork.Running then
-      begin
-        FController.FNetwork.UpdateState(XvtrTranslate(FController.FCenterFreq), XvtrTranslate(ActiveTXFreqHz), FController.FDriveLevel, FController.FTransmitting, True, True);
-        FController.FNetwork.SendFullHP;
-      end;
-      FSpectrumDirty := True;
-    end;
   end;
 end;
 

RadioController.pas

@@ -571,7 +571,31 @@ begin
 end;
 
 procedure TRadioController.SetVfoB(Hz: Double);
-begin FVfoB := Hz; Changed(rfVfoB); { TODO wiring } end;
+// VFO B всегда сохраняется. Если B активен — перестраиваем приёмник (DDC=VFO B,
+// без CTUN, сдвиг 0), детектим диапазон и толкаем в сеть. Если B неактивен
+// (split, слушаем A) — только сохраняем частоту (используется для TX).
+// Рендер FreqDispB/спектра — в UI через OnControllerState(rfVfoB).
+var BandIdx: Integer;
+begin
+  FVfoB := Hz;
+  if FActiveVfo = 1 then
+  begin
+    FCenterFreq := FVfoB;
+    if FWDSPReady and Assigned(FDSPEngine) then FDSPEngine.SetShift(0.0);
+    if FCurrentXvtr < 0 then
+    begin
+      BandIdx := FreqToBandIdx(FVfoB);
+      if (BandIdx >= 0) and (BandIdx <> FCurrentBand) then
+      begin
+        FCurrentBand := BandIdx;
+        FDriveLevel  := CalcDriveByte;
+        Changed(rfBand);
+      end;
+    end;
+    PushNetworkState;
+  end;
+  Changed(rfVfoB);
+end;
 
 procedure TRadioController.SetActiveVfo(Idx: Integer);
 begin FActiveVfo := Idx; Changed(rfActiveVfo); { TODO wiring: ActivateVfo } end;