fix web TX spectrum position in CTUN mode

Add 'dup' field to state JSON (FDisplayDuplex). In CTUN+non-DUP TX,
use vfo_a_hz as spectrum center so the TX signal renders at the VFO
position instead of the display center. In CTUN+DUP TX, keep center_hz
so the RX spectrum stays correctly positioned at the filter.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

MainForm.pas

@@ -2776,7 +2776,7 @@ begin
       FCenterFreq, FFilter,
       FVfoB, FActiveVfo,
       FTransmitting, TrkDrive.Position,
-      FAtten, FTuning);
+      FAtten, FTuning, FDisplayDuplex);
 end;
 
 // ===========================================================================

WebPageHtml.pas

@@ -410,7 +410,9 @@ begin
     'Object.keys(msg).forEach(function(k){var pk=PEND_MAP[k];if(!pk||!isPending(pk))cur[k]=msg[k];});' +
     // Обновляем localCenter/localSpan из сервера только когда пользователь не тянет
     'if(!dragging&&Date.now()-wheelActiveTs>300){' +
-    'if(msg.center_hz!=null)localCenter=msg.center_hz;' +
+    // В CTUN без DUP: TX-спектр WDSP центрирован по vfo_a_hz, а не по DDC LO.
+    // В CTUN с DUP: показываем RX-спектр → center_hz остаётся.
+    'if(msg.center_hz!=null)localCenter=(cur.transmitting&&cur.ctun&&!cur.dup)?cur.vfo_a_hz:msg.center_hz;' +
     'if(msg.span_hz!=null)localSpan=msg.span_hz||192000;' +
     '}' +
     'if(!isPending("freq")){vfoA=cur.vfo_a_hz||vfoA;}' +

WebServer.pas

@@ -218,6 +218,7 @@ type
     FAttnIdx:     Integer;
     FOnTun:       TWebCmdTun;
     FTuning:      Boolean;
+    FDuplex:      Boolean;
 
     FWebClientActive: Boolean;
 
@@ -262,7 +263,7 @@ type
       CenterHz: Double; FilterIdx: Integer;
       VfoB: Double; ActiveVfo: Integer;
       Transmitting: Boolean; DriveLevel: Integer;
-      AttnIdx: Integer; Tuning: Boolean);
+      AttnIdx: Integer; Tuning: Boolean; Duplex: Boolean);
 
     property WebClientActive: Boolean read FWebClientActive;
 
@@ -1133,7 +1134,7 @@ begin
       '"wf_agc":%s,"wf_nf":%s,"band_idx":%d,"smeter_dbm":%.1f,' +
       '"running":%s,"mute":%s,"ctun":%s,' +
       '"nr_mode":%d,"nr":%s,"nb_mode":%d,"nb":%s,"snb":%s,"anf":%s,"connected":%s,' +
-      '"transmitting":%s,"drive":%d,"attn_idx":%d,"tuning":%s}',
+      '"transmitting":%s,"drive":%d,"attn_idx":%d,"tuning":%s,"dup":%s}',
       [FFreq, FVfoB, FActiveVfo,
        FMode, MODE_N[FMode mod 8],
        FFilterIdx, FFilterBW,
@@ -1155,7 +1156,8 @@ begin
        BoolToStr(FTransmitting, 'true', 'false'),
        FDriveLevel,
        FAttnIdx,
-       BoolToStr(FTuning, 'true', 'false')
+       BoolToStr(FTuning,  'true', 'false'),
+       BoolToStr(FDuplex, 'true', 'false')
       ]);
   finally
     FStateLock.Leave;
@@ -1222,7 +1224,7 @@ procedure TWebServer.PushSpectrum(
   CenterHz: Double; FilterIdx: Integer;
   VfoB: Double; ActiveVfo: Integer;
   Transmitting: Boolean; DriveLevel: Integer;
-  AttnIdx: Integer; Tuning: Boolean);
+  AttnIdx: Integer; Tuning: Boolean; Duplex: Boolean);
 var N, i: Integer;
 begin
   if not FRunning then Exit;
@@ -1258,6 +1260,7 @@ begin
     FDriveLevel   := DriveLevel;
     FAttnIdx      := AttnIdx;
     FTuning       := Tuning;
+    FDuplex       := Duplex;
   finally
     FStateLock.Leave;
   end;