Controls: the keyboard bridges STAND DOWN for a live device (step 2c)

New engine query BTRIODevicePresent() (L4CTRL.cpp, ungated -- pod-correct for
the serial RIO too): device exists AND IsOperational().  Both dev input
bridges -- the mech4.cpp mapper-attr writes and the mechmppr.cpp BT_KEY_BRIDGE
block -- now gate their WRITES on it: BT_KEY_BRIDGE unset = auto (bridge only
when no device), 0 = force off (the documented pod setting, honored), else
force on.  The BT_FORCE_THROTTLE headless harness always rides the bridge.
The mapper demand READ (turn = turnDemand) always runs.

Verified live (glass build, PAD): OS-injected LSHIFT hold slews the PadRIO
throttle 0 -> 0.33 -> 1.0 with pre==thr every frame -- the value arrives via
the ENGINE push through the streamed .CTL binding, not the bridge -- and
speedDemand=61.501 comes out of the authentic InterpretControls.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

engine/MUNGA_L4/L4CTRL.cpp

@@ -1174,6 +1174,29 @@ void
 }
 
 //
+//############################################################################
+// Game-side device query (glass-cockpit step 2c): True when a real cockpit
+// device (serial RIO on the pod, PadRIO under BT_GLASS) is present AND
+// delivering input.  The game's dev keyboard input bridges (mech4.cpp,
+// mechmppr.cpp) stand down then -- they would clobber the device's engine
+// push every frame.  This automates the documented pod intent
+// ("BT_KEY_BRIDGE=0 to disable on pods").
+//############################################################################
+//
+int
+	BTRIODevicePresent(void)
+{
+	if (application == NULL)
+	{
+		return 0;
+	}
+	LBE4ControlsManager *controls =
+		(LBE4ControlsManager *)application->GetControlsManager();
+	return controls != NULL
+		&& controls->rioPointer != NULL
+		&& controls->rioPointer->IsOperational();
+}
+
 //############################################################################
 // Execute
 //