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.c

@@ -33,6 +33,30 @@ Block* block_create(BlockType type, float x, float y) {
     return block;
 }
 
+// 复制积木 (深拷贝，不复制连接关系)
+Block* block_copy(const Block* src) {
+    if (!src) return NULL;
+    Block* block = (Block*)malloc(sizeof(Block));
+    if (!block) return NULL;
+    memcpy(block, src, sizeof(Block));
+    
+    // 重新设置拥有者，断开所有连接
+    for (int i = 0; i < MAX_BLOCK_INPUTS; i++) {
+        block->inputs[i].owner = block;
+        block->inputs[i].connected = NULL;
+    }
+    for (int i = 0; i < MAX_BLOCK_OUTPUTS; i++) {
+        block->outputs[i].owner = block;
+        block->outputs[i].connected = NULL;
+    }
+    block->next = NULL;
+    block->parent_if = NULL;
+    block->workspace = NULL;
+    block->user_data = NULL;
+    
+    return block;
+}
+
 // 销毁积木
 void block_destroy(Block* block) {
     if (!block) return;