Glass panel flicker FIXED: layered window + lamp-period repaint timer (issue #13)

Human-verified (epilectrik, live): the panel is steady on the SAME monitor
as the game.  Two root causes, both cured:
1. D3D-vs-GDI presentation contention -- the game's ~60Hz presents fought
   the panel's GDI redraws on a shared display (single-monitor users had
   no escape; moving the panel to another monitor cleaned it, the tell).
   WS_EX_LAYERED + opaque SetLayeredWindowAttributes: DWM now composites
   the panel independently of the D3D swap chain.
2. Sampling beat -- the 100ms repaint timer sampled the authentic RIO lamp
   flash half-periods (125/250/500ms) into an irregular 'broken lamp'
   strobe.  Timer -> 62ms (~half the fastest half-period): flashing lamps
   now blink at their even, authored tempo.
(Stacked on the earlier double-buffer/erase-suppression cleanup.)

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

engine/MUNGA_L4/L4PADPANEL.cpp

@@ -37,7 +37,9 @@ enum
 	PanelMargin = 6,
 	FirstRow = 1,			// the shared layout leaves grid row 0 empty
 	RepaintTimerId = 1,
-	RepaintMilliseconds = 100
+	RepaintMilliseconds = 62	// issue #13: ~half the fastest lamp-flash half-period
+								// (125ms) -- the old 100ms SAMPLED the 125/250/500ms
+								// flash rhythms into an irregular "broken lamp" beat
 };
 
 enum GroupKind { KindMfd, KindColumn, KindKeypad };
@@ -551,8 +553,13 @@ void
 		panel_x = 0;
 	}
 
+	// Issue #13: WS_EX_LAYERED -- a layered window is composited by DWM
+	// independently of the game's D3D swap chain, ending the D3D-vs-GDI
+	// presentation contention that strobed the panel on the game's monitor
+	// (single-monitor setups had no escape).  Fully opaque; behavior is
+	// otherwise identical.
 	panelWindow = CreateWindowExW(
-		WS_EX_TOPMOST,
+		WS_EX_TOPMOST | WS_EX_LAYERED,
 		L"BTPadPanelWnd", L"BattleTech - Cockpit Buttons",
 		style,
 		panel_x, 12,
@@ -563,6 +570,7 @@ void
 		DEBUG_STREAM << "[padpanel] CreateWindow failed\n" << std::flush;
 		return;
 	}
+	SetLayeredWindowAttributes(panelWindow, 0, 255, LWA_ALPHA);	// opaque layer
 	SetTimer(panelWindow, RepaintTimerId, RepaintMilliseconds, NULL);
 	ShowWindow(panelWindow, SW_SHOWNOACTIVATE);
 	DEBUG_STREAM << "[padpanel] cockpit button panel up ("