Refresh selected-building panel when paused player commands drain

src/lib/eventsystem/event/PlayerCommandsAppliedEvent.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include "Event.h"
+
+// Emitted by GameWorldView once per frame after queued player commands have been
+// drained and applied to the simulation. It lets presentation widgets refresh
+// even while the game is paused (no tick advances, so no TickAdvancedEvent), for
+// example so a shipyard's layout preview appears immediately after its schematic
+// is chosen. It is a UI notification only and never feeds back into the command
+// queue, so it has no effect on replay recording or determinism.
+class PlayerCommandsAppliedEvent : public Event
+{
+};