feat: Pluto/AD936x SDR backend (discovery, RX, VHF band plan)

Add ADALM-Pluto / AD9361 support as a second hardware backend alongside
openHPSDR, sharing the WDSP DSP pipeline and the existing controller API
(UI stays decoupled from logic).

- RadioBackend.pas: abstract TRadioBackend + TBackendCaps + TRadioDevice
  (Kind/URI/Serial). THPSDRNetwork now derives from it (state via virtual
  getters); TRadioController.FNetwork is the base type.
- IIOBindings.pas: dynamic libiio loader (runs without libiio present).
- PlutoBackend.pas: scan/probe-by-URI, connect, LO/rate/bandwidth/gain
  control, RX streaming thread (int16->24bit BE -> OnDDCIQ), Q conjugated
  to match WDSP IQ convention. Verified on LibreSDR (AD9361) over network.
- Unified discovery: TDiscoverThread scans both backends; network Plutos
  found via direct ProbeURI (no mDNS needed). ConnectDevice dispatches by
  Dev.Kind (EnsureBackend swaps backend, preserving callbacks).
- DeviceStore/DeviceForm: persist Kind/URI/Serial; save Pluto via
  AddSavedPluto so saved/autostart devices reconnect across restarts.
- VHF/UHF band plan (BoardUtils, kind-aware): 6m..ADS-B for Pluto; fixes
  HF clamps (band detect, mouse-wheel 60 MHz cap, freq-display max).
- SampleRateOverlay: configurable presets (Pluto 576k..5760k, >520 ksps),
  auto-width to fit.

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

DeviceStore.pas

@@ -11,7 +11,7 @@ unit DeviceStore;
 interface
 
 uses
-  Classes, SysUtils, IniFiles, BoardUtils, PlatformUtils;
+  Classes, SysUtils, IniFiles, BoardUtils, PlatformUtils, RadioBackend;
 
 const
   DEVICE_CFG_NAME = 'hpsdr_devices.ini';
@@ -23,6 +23,9 @@ type
     IPAddress: string;
     BoardType: Integer;
     AutoStart: Boolean;  // запускать автоматически при старте
+    Kind:      TBackendKind;   // bkHPSDR / bkPluto
+    URI:       string;         // Pluto: 'ip:..' / 'usb:..'
+    Serial:    string;         // Pluto serial
   end;
 
   // Найденное устройство (результат discovery)
@@ -31,6 +34,9 @@ type
     DisplayName: string;
     BoardType:   Integer;
     MAC:         array[0..5] of Byte;   // нужен для preload-rate lookup (LoadDevice по MAC)
+    Kind:        TBackendKind;          // bkHPSDR / bkPluto
+    URI:         string;                // Pluto: context URI
+    Serial:      string;                // Pluto serial
   end;
 
   { TDeviceStore }
@@ -50,6 +56,8 @@ type
     function  Saved(Idx: Integer): TSavedDevice;
     // Добавляет запись (Name пустое → 'HPSDR'); возвращает индекс новой записи.
     function  AddSaved(const AName, IP: string; BoardType: Integer): Integer;
+    // Добавляет Pluto-устройство (Kind=bkPluto) с URI/Serial.
+    function  AddSavedPluto(const AName, AURI, ASerial: string): Integer;
     procedure RemoveSaved(Idx: Integer);
     procedure SetAutoStart(Idx: Integer);   // эксклюзивно: только одно autostart
     function  AutoStartIP: string;
@@ -60,7 +68,9 @@ type
     // ---- Найденные (discovery) ----
     procedure ClearDiscovered;
     procedure AddDiscovered(const IP, DisplayName: string; BoardType: Integer;
-                            const MAC: array of Byte);
+                            const MAC: array of Byte;
+                            Kind: TBackendKind = bkHPSDR;
+                            const URI: string = ''; const Serial: string = '');
     function  DiscoveredCount: Integer;
     function  Discovered(Idx: Integer): TDiscoveredDevice;
     // IP найденного устройства по IP (для preload-rate lookup и т.п.)
@@ -100,6 +110,9 @@ begin
       FSaved[I].IPAddress := Ini.ReadString (Section, 'IP',        '');
       FSaved[I].BoardType := Ini.ReadInteger(Section, 'BoardType', 0);
       FSaved[I].AutoStart := Ini.ReadBool   (Section, 'AutoStart', False);
+      FSaved[I].Kind      := TBackendKind(Ini.ReadInteger(Section, 'Kind', 0));
+      FSaved[I].URI       := Ini.ReadString (Section, 'URI',       '');
+      FSaved[I].Serial    := Ini.ReadString (Section, 'Serial',    '');
       Inc(FSavedCount);
     end;
   finally
@@ -123,6 +136,9 @@ begin
       Ini.WriteString (Section, 'IP',        FSaved[I].IPAddress);
       Ini.WriteInteger(Section, 'BoardType', FSaved[I].BoardType);
       Ini.WriteBool   (Section, 'AutoStart', FSaved[I].AutoStart);
+      Ini.WriteInteger(Section, 'Kind',      Ord(FSaved[I].Kind));
+      Ini.WriteString (Section, 'URI',       FSaved[I].URI);
+      Ini.WriteString (Section, 'Serial',    FSaved[I].Serial);
     end;
   finally
     Ini.Free;
@@ -155,6 +171,25 @@ begin
   FSaved[Result].IPAddress := Trim(IP);
   FSaved[Result].BoardType := BoardType;
   FSaved[Result].AutoStart := False;
+  FSaved[Result].Kind      := bkHPSDR;
+  FSaved[Result].URI       := '';
+  FSaved[Result].Serial    := '';
+  SaveSaved;
+end;
+
+function TDeviceStore.AddSavedPluto(const AName, AURI, ASerial: string): Integer;
+begin
+  Result := FSavedCount;
+  Inc(FSavedCount);
+  SetLength(FSaved, FSavedCount);
+  if Trim(AName) <> '' then FSaved[Result].Name := Trim(AName)
+  else                      FSaved[Result].Name := 'PlutoSDR';
+  FSaved[Result].IPAddress := Trim(AURI);   // в списке показываем URI
+  FSaved[Result].BoardType := 0;
+  FSaved[Result].AutoStart := False;
+  FSaved[Result].Kind      := bkPluto;
+  FSaved[Result].URI       := Trim(AURI);
+  FSaved[Result].Serial    := Trim(ASerial);
   SaveSaved;
 end;
 
@@ -233,7 +268,7 @@ begin
 end;
 
 procedure TDeviceStore.AddDiscovered(const IP, DisplayName: string; BoardType: Integer;
-  const MAC: array of Byte);
+  const MAC: array of Byte; Kind: TBackendKind; const URI: string; const Serial: string);
 var
   Idx, J: Integer;
 begin
@@ -243,6 +278,9 @@ begin
   FDiscovered[Idx].IPAddress   := IP;
   FDiscovered[Idx].DisplayName := DisplayName;
   FDiscovered[Idx].BoardType   := BoardType;
+  FDiscovered[Idx].Kind        := Kind;
+  FDiscovered[Idx].URI         := URI;
+  FDiscovered[Idx].Serial      := Serial;
   FillChar(FDiscovered[Idx].MAC, SizeOf(FDiscovered[Idx].MAC), 0);
   for J := 0 to High(MAC) do
     if J <= 5 then FDiscovered[Idx].MAC[J] := MAC[J];