Merge glass-per-display-windows: per-display cockpit windows (Cyd, BT_GLASS_PANELS)

One window per pod display (Heat/Engineering/Comm/Weapons x2/radar +
Flight Controls), each carrying its surface with its RIO button bank
arranged pod-faithfully; CPU-expanded surfaces, buttons under the
imagery.  Runtime gate BT_GLASS_PANELS (=0 = the legacy single panel).
Merged on top of today's landed fix pile (audio-crash, experience,
parallax); the L4PADRIO overlap with the gait-detent commit resolved
preserving BOTH (his window refactor + our at-rest band snap).

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

# Conflicts:
#	context/glass-cockpit.md

engine/MUNGA_L4/L4PADRIO.cpp

@@ -9,6 +9,7 @@
 
 #include "l4padrio.h"
 #include "l4padpanel.h"
+#include "l4glasswin.h"
 #include "l4ctrl.h"
 
 #include <windows.h>
@@ -168,10 +169,16 @@ PadRIO::PadRIO():
 		<< "live on focus; L4PADFLIP=" << flipStickAxes << ")\n" << std::flush;
 
 	//
-	// The on-screen cockpit button panel (step 2d) rides the device: the
-	// glass preset sets BT_PAD_PANEL=1.
+	// The on-screen cockpit buttons ride the device.  BT_GLASS_PANELS (the
+	// glass preset default) breaks each secondary display into its own window
+	// with its RIO bank around it; otherwise the single combined pad panel
+	// (BT_PAD_PANEL=1) is used.
 	//
-	if (getenv("BT_PAD_PANEL") != NULL && *getenv("BT_PAD_PANEL") != '0')
+	if (BTGlassPanelsActive())
+	{
+		BTGlassPanels_Create();
+	}
+	else if (getenv("BT_PAD_PANEL") != NULL && *getenv("BT_PAD_PANEL") != '0')
 	{
 		BTPadPanel_Create();
 	}
@@ -179,6 +186,7 @@ PadRIO::PadRIO():
 
 PadRIO::~PadRIO()
 {
+	BTGlassPanels_Destroy();	// safe no-op if the glass windows were never created
 	BTPadPanel_Destroy();
 	if (activeInstance == this)
 	{