Fix IQ data flow: send HP Run=1 before DDC/DUC Specific packets

The emulator (and real hardware) creates ddc_specific_thread (port 1025),
duc_specific_thread (port 1026), and rx_thread[0..3] (ports 1035+) only
after receiving HP Run=1. Previously ConfigureDDCs and SendDUCSpecific
were sent before SetRunAndFreq(True), so both packets arrived at closed
ports and were silently dropped — ddcenable remained -1, rx_thread slept
forever, no IQ data ever arrived, and the 5-second timeout fired Run=0.

Fix: reorder DoConnectDevice to send Run=1 first, then DDC/DUC Specific.
Also add keepalive resend of the cached DDC Specific packet every 500 ms
for the first 5 seconds after start, to handle thread-startup races on
real hardware over the network.

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

HPSDRNetwork.pas

@@ -121,6 +121,11 @@ type
     FPortDUCIQ:    Word;
     FDirectIP:     string;   // для unicast discovery
 
+    // Кэш DDC Specific — keepalive повторно шлёт первые 5 сек после старта
+    FCachedDDCSpec:  TDDCSpecificPacket;
+    FCachedDDCValid: Boolean;
+    FResendCount:    Integer;
+
     // Текущее состояние для построения HP пакетов
     FCurrentRXFreq:  Double;
     FCurrentTXFreq:  Double;
@@ -398,6 +403,15 @@ begin
     if not FNet.FConnected then Continue;
     // Отправляем полный HP с частотами и ALEX — как piHPSDR
     FNet.SendFullHP;
+    // Повторно отправляем DDC Specific первые 5 сек после Run=1 (каждые 500 мс).
+    // ddc_specific_thread на эмуляторе/железе стартует ПОСЛЕ получения Run=1,
+    // поэтому первый ConfigureDDCs может прийти раньше чем порт 1025 откроется.
+    if FNet.FRunning and FNet.FCachedDDCValid then
+    begin
+      Inc(FNet.FResendCount);
+      if (FNet.FResendCount <= 100) and (FNet.FResendCount mod 10 = 2) then
+        FNet.SendDDCSpecific(FNet.FCachedDDCSpec);
+    end;
   end;
 end;
 
@@ -914,6 +928,9 @@ begin
   end;
 
   SendDDCSpecific(Pkt);
+  FCachedDDCSpec  := Pkt;
+  FCachedDDCValid := True;
+  FResendCount    := 0;
 end;
 
 procedure THPSDRNetwork.SendDUCSpecific(const Pkt: TDUCSpecificPacket);