feat: Pluto support in headless daemon (connect/autostart/discover/dev_add) + headless audio

The headless daemon (ewsdrd) only ever built HPSDR devices, so Pluto
could not be used: backend is chosen by Dev.Kind and Pluto opens by URI,
neither of which the daemon propagated. Also local audio played on the
host and web Discover never probed network Plutos.

Shared, backend-agnostic helpers in TRadioController (used by GUI + daemon):
- ResolveDevice(IP): discovered->saved lookup restoring Kind/URI/Serial/
  BoardType/MAC. MainForm.ResolveDevice now delegates here.
- AddSavedDevice(name, addr): web dev_add saves Pluto when addr has a URI
  scheme (ip:/usb:/local:), else HPSDR. Both web hosts use it.
- SeedPlutoProbeFromSaved: seed network-probe URIs from saved Plutos
  (no mDNS -> a network Pluto is only found by direct URI probe).
- LocalAudioEnabled flag (GUI=True): when False the local sound card is
  neither opened nor written; RX audio goes only to web (OnAudioConsume).

DeviceStore.AutoStartDevice(out Dev): full autostart record (Kind/URI/
Serial) so a saved Pluto (URI-addressed, empty IPAddress on USB) can
autostart.

Daemon (ewsdrd.lpr): LocalAudioEnabled:=False; SyncConnect via
ResolveDevice; autostart via AutoStartDevice; SyncDiscover seeds probe
URIs then Discover; SyncDevAdd via AddSavedDevice.

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

DeviceStore.pas

@@ -62,6 +62,9 @@ type
     procedure SetAutoStart(Idx: Integer);   // эксклюзивно: только одно autostart
     function  AutoStartIP: string;
     function  AutoStartBoardType: Integer;
+    // Полная autostart-запись (Kind/URI/Serial) — для бэкенд-агностичного автозапуска
+    // (Pluto открывается по URI, у USB-Pluto IPAddress пуст). False — нет autostart.
+    function  AutoStartDevice(out Dev: TSavedDevice): Boolean;
     function  SavedBoardType(Idx: Integer): Integer;
     function  SavedDisplay(Idx: Integer): string;   // строка для списка (с * и board)
 
@@ -242,6 +245,19 @@ begin
     end;
 end;
 
+function TDeviceStore.AutoStartDevice(out Dev: TSavedDevice): Boolean;
+var
+  I: Integer;
+begin
+  Result := False;
+  for I := 0 to FSavedCount - 1 do
+    if FSaved[I].AutoStart then
+    begin
+      Dev := FSaved[I];
+      Exit(True);
+    end;
+end;
+
 function TDeviceStore.SavedBoardType(Idx: Integer): Integer;
 begin
   if (Idx >= 0) and (Idx < FSavedCount) then