Phase 3 (batch 2): route AGC mode through controller command

TRadioController.SetAGCMode now owns the index->WDSP mapping, applies to
the DSP engine, and updates the band cache, then fires OnStateChanged.
OnControllerState restyles the AGC button group. BtnAGCModeClick,
OnVfoOverlayAGCChange, and SyncWebAGC all call the command.

Fixes a latent web bug: SyncWebAGC used TWDSPAGCMode(index) directly,
mapping the UI index (0=FAST..4=OFF) onto the wrong enum (0=OFF...), so
web AGC selections set the wrong DSP mode. The button/overlay path used
the correct AGCModes[] array; unifying on the command applies that to web
too. Buttons/overlay behavior unchanged.

Builds clean (cocoa).

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

MainForm.pas

@@ -1420,6 +1420,8 @@ end;
 // маршалятся адаптерами). FSyncingFromController защищает от рекурсии, когда
 // программное изменение виджета триггерит его OnChange.
 procedure TMainForm.OnControllerState(Sender: TObject; Field: TRadioField);
+var
+  i: Integer;
 begin
   FSyncingFromController := True;
   try
@@ -1435,6 +1437,8 @@ begin
       rfNB:  UpdateNBButton;
       rfSNB: UpdateSNBButton;
       rfANF: UpdateANFButton;
+      rfAGCMode:
+        for i := 0 to 4 do StyleButton(BtnAGCMode[i], i = FController.FAGCMode);
     end;
   finally
     FSyncingFromController := False;
@@ -6086,16 +6090,8 @@ begin
 end;
 
 procedure TMainForm.OnVfoOverlayAGCChange(AGCMode: Integer);
-const
-  AGCModes: array[0..4] of TWDSPAGCMode = (agcFast, agcMedium, agcSlow, agcLong, agcOff);
-var
-  I: Integer;
 begin
-  FController.FAGCMode := AGCMode;
+  FController.SetAGCMode(AGCMode);
-  for I := 0 to 4 do StyleButton(BtnAGCMode[I], I = AGCMode);
-  if FController.FWDSPReady then
-    FController.FDSPEngine.SetAGC(AGCModes[AGCMode], 50.0);
-  FController.FBandCache[FController.FCurrentBand].AGCMode := FController.FAGCMode;
 end;
 
 procedure TMainForm.OnVfoOverlayInvalidate(Sender: TObject);
@@ -6292,14 +6288,8 @@ begin
 end;
 
 procedure TMainForm.SyncWebAGC;
-var i: Integer;
 begin
-  if (FWebSyncInt < 0) or (FWebSyncInt > 4) then Exit;
+  FController.SetAGCMode(FWebSyncInt);   // единый маппинг (исправляет старый web-баг)
-  FController.FAGCMode := FWebSyncInt;
-  for i := 0 to 4 do StyleButton(BtnAGCMode[i], i = FController.FAGCMode);
-  if FController.FWDSPReady then
-    FController.FDSPEngine.SetAGC(TWDSPAGCMode(FController.FAGCMode), 50.0);
-  FController.FBandCache[FController.FCurrentBand].AGCMode := FController.FAGCMode;
 end;
 
 procedure TMainForm.WebOnAGCTop(DB: Integer);
@@ -7296,18 +7286,9 @@ end;
 
 
 procedure TMainForm.BtnAGCModeClick(Sender: TObject);
-const
-  AGCModes: array[0..4] of TWDSPAGCMode = (
-    agcFast, agcMedium, agcSlow, agcLong, agcOff);
-var
-  i, N: Integer;
 begin
-  N := (Sender as TFlatButton).Tag;
+  if FSyncingFromController then Exit;
-  FController.FAGCMode := N;
+  FController.SetAGCMode((Sender as TFlatButton).Tag);
-  for i := 0 to 4 do StyleButton(BtnAGCMode[i], i = N);
-  if FController.FWDSPReady then
-    FController.FDSPEngine.SetAGC(AGCModes[N], 50.0);
-  FController.FBandCache[FController.FCurrentBand].AGCMode := FController.FAGCMode;
 end;
 
 procedure TMainForm.TrkAGCChange(Sender: TObject);

RadioController.pas

@@ -382,7 +382,17 @@ procedure TRadioController.SetFilterBW(BWHz: Integer);
 begin FFilterBW := BWHz; Changed(rfFilterBW); { TODO wiring } end;
 
 procedure TRadioController.SetAGCMode(M: Integer);
-begin FAGCMode := M; Changed(rfAGCMode); { TODO wiring: FDSPEngine.SetAGC } end;
+const
+  // UI-индекс 0..4 (FAST/MED/SLOW/LONG/OFF) -> WDSP enum. Единый маппинг для
+  // всех фронтендов (раньше web ошибочно кастовал индекс прямо в enum).
+  AGCModes: array[0..4] of TWDSPAGCMode = (agcFast, agcMedium, agcSlow, agcLong, agcOff);
+begin
+  if (M < 0) or (M > 4) then Exit;
+  FAGCMode := M;
+  if FWDSPReady and Assigned(FDSPEngine) then FDSPEngine.SetAGC(AGCModes[M], 50.0);
+  FBandCache[FCurrentBand].AGCMode := FAGCMode;
+  Changed(rfAGCMode);
+end;
 
 procedure TRadioController.SetAGCTop(DB: Integer);
 begin FAGCTop := DB; Changed(rfAGCTop); { TODO wiring } end;