fix: skip empty VBA modules during extraction to avoid creating unnecessary files

- Add check in _process_module() to detect modules with no actual code content
- Display skip message for empty modules instead of creating files
- Prevent empty modules from being added to metadata

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

extract_vba.py

@@ -305,6 +305,11 @@ class VBAExtractor:
         # 解析Attribute信息
         attributes, clean_code = self.parse_attributes(vba_code)
 
+        # 检查是否有实际代码内容（跳过空模块）
+        if not clean_code.strip():
+            print(f"  [跳过] {module_name} - 无实际代码内容")
+            return
+
         # 确定实际的模块类型
         module_type = self._determine_module_type(module_name, category)