Phase 5 (batch 27): move Run=0 teardown (StopRunning) into the controller

Extract the graceful Run=0 teardown from BtnStartStopClick's STOP branch
into TRadioController.StopRunning: UpdateState/SetRunAndFreq(False) at zero
drive, clear FRunning/FTransmitting, SetTXRun(False), reset RX telemetry,
emit Changed(rfTransmitting) + rfRunning. The network stays Connected so the
UI wrapper can persist state before Disconnect.

New OnControllerState(rfRunning) render handles the START/STOP button,
BtnMOX.Enabled and sleep inhibit; the context-specific offline status text
stays with the caller. FormClose reuses StopRunning (same teardown).

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

RadioController.pas

@@ -372,6 +372,7 @@ type
     // Жизненный цикл движка / устройства
     procedure StartStop;
     procedure SetRun(On_: Boolean);
+    procedure StopRunning;   // Run=0: graceful-стоп RX-потока + сброс TX/телеметрии
     procedure ConnectDevice(const Dev: THPSDRDevice);
     procedure Discover;
 
@@ -1824,6 +1825,25 @@ begin SetRun(not FRunning); end;
 procedure TRadioController.SetRun(On_: Boolean);
 begin FRunning := On_; Changed(rfRunning); { TODO wiring: логика BtnStartStopClick } end;
 
+procedure TRadioController.StopRunning;
+// Graceful-останов RX-потока (Run=0) + сброс TX и RX-телеметрии. Сеть остаётся
+// Connected — Disconnect отдельно (UI-обёртка делает это после persistence).
+// Рендер run-кнопки/sleep — UI через OnControllerState(rfRunning); MOX — rfTransmitting.
+begin
+  if FRunning then
+  begin
+    FNetwork.UpdateState(XvtrTranslate(FCenterFreq), XvtrTranslate(ActiveTXFreqHz), 0, False, True, True);
+    FNetwork.SetRunAndFreq(False, XvtrTranslate(FCenterFreq), XvtrTranslate(FCenterFreq), 0);
+    FRunning      := False;
+    FTransmitting := False;
+    if FWDSPReady then FDSPEngine.SetTXRun(False);
+    Changed(rfTransmitting);   // MOX-кнопка off
+  end;
+  FRXPacketCount := 0;
+  FActiveDDC     := 0;
+  Changed(rfRunning);   // безусловный сброс run-кнопки/MOX.Enabled/sleep (как старый хвост STOP)
+end;
+
 procedure TRadioController.ConnectDevice(const Dev: THPSDRDevice);
 begin { TODO wiring: DoConnectDevice } Changed(rfDevice); end;