feat: major engine overhaul - scene demo with lighting, sphere, ground

- Scene Demo: cube + sphere + ground plane with proper lighting
- Audio: XAudio2 dynamic loading + WAV playback
- Physics: expanded collision system
- Renderer: improved pipeline with materials
- UI: extended widget system
- VisualScript: enhanced serializer + block interactions
- ASM: optimized math/memory/profiling routines
- Window: mouse input + scroll support

Engine/VisualScript/block_core.h

@@ -171,6 +171,7 @@ typedef struct BlockConnection {
 
 // 函数声明
 Block* block_create(BlockType type, float x, float y);
+Block* block_copy(const Block* src);
 void block_destroy(Block* block);
 BlockSlot* block_add_input(Block* block, SlotKind kind, SlotValueType value_type, const char* label);
 BlockSlot* block_add_output(Block* block, SlotKind kind, SlotValueType value_type, const char* label);