feat: unify band plan across desktop + web UIs

Web band selector was hardcoded to the HF plan, so on Pluto it showed
160m..6m instead of the VHF/UHF plan and highlighted the wrong entry
(band switching itself already worked: web sends idx, controller maps it
via the IsPluto plan). Mirror the sample-rate unification.

Single source of truth = BoardUtils -> controller:
- BoardUtils: TBandInfo/TBandPlanArray + BuildBandPlan(Pluto).
- TRadioController.BandPlan returns BuildBandPlan(IsPluto).

Both UIs derive from it:
- Desktop already plan-aware (RelabelBands + RestoreBand) - unchanged.
- Web: WebServer.SetBands + "bands" in state JSON; hosts push
  BandPlan on connect/startup; JS builds the band selector from
  state.bands (BAND_N/BAND_F now dynamic).

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

ewsdrd.lpr

@@ -28,7 +28,7 @@ uses
   {$IFDEF UNIX}cthreads, BaseUnix,{$ENDIF}
   Classes, SysUtils,
   RadioController, WebServer, WebAdapter,
-  HPSDRNetwork, Settings, WDSP, PlatformUtils, DeviceStore;
+  HPSDRNetwork, Settings, WDSP, PlatformUtils, DeviceStore, BoardUtils;
 
 const
   DAEMON_SPEC_WIDTH = 1024;   // ширина спектра для StartRunning (web-буфер = 1024)
@@ -56,6 +56,7 @@ type
     procedure PushDeviceList;
     procedure PushXvtr;
     procedure PushRatePresets;   // sample-rate пресеты бэкенда → web
+    procedure PushBands;         // band-план бэкенда → web
     // Входящие web-команды (из WS-потока): запоминаем параметр и маршалим в Sync*.
     procedure WebRun(On_: Boolean);
     procedure WebConnect(const IP: string);
@@ -197,7 +198,7 @@ begin
   // выходные web-списки, которых нет в периодическом PushState.
   case Field of
     rfDeviceList: PushDeviceList;             // discovered обновился
-    rfXvtr, rfDevice: begin PushXvtr; PushDeviceList; PushRatePresets; end;  // connect / xvtr / backend
+    rfXvtr, rfDevice: begin PushXvtr; PushDeviceList; PushRatePresets; PushBands; end;  // connect / xvtr / backend
   end;
 end;
 
@@ -297,6 +298,24 @@ begin
   FWeb.SetRatePresets(FCtrl.SampleRatePresets);
 end;
 
+procedure THeadlessHost.PushBands;
+var
+  Plan: TBandPlanArray;
+  Names: array of string;
+  Freqs: array of Double;
+  i: Integer;
+begin
+  Plan := FCtrl.BandPlan;
+  SetLength(Names, Length(Plan));
+  SetLength(Freqs, Length(Plan));
+  for i := 0 to High(Plan) do
+  begin
+    Names[i] := Plan[i].Name;
+    Freqs[i] := Plan[i].FreqHz;
+  end;
+  FWeb.SetBands(Names, Freqs);
+end;
+
 // --- Входящие web-команды (WS-поток) → маршалинг в главный поток ---
 
 procedure THeadlessHost.WebRun(On_: Boolean);
@@ -389,6 +408,7 @@ begin
   Log('Web control on http://' + WebCfg.BindAddr + ':' + IntToStr(WebCfg.Port));
   PushDeviceList;
   PushRatePresets;   // дефолтный бэкенд (HPSDR) до connect; перезапишется на смене
+  PushBands;
 
   // FRunning ставим ДО autostart: первый WDSP-open может занять время, и если за
   // него прилетит SIGINT (RequestStop→FRunning:=False), цикл сразу завершится, а