rename: IUP 库目录重命名为 libs/IUP

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

libs/IUP/include/iupfiledlg.h

@@ -0,0 +1,24 @@
+/** \file
+ * \brief New FileDlg (Windows Only).
+ *
+ * See Copyright Notice in "iup.h"
+ */
+ 
+#ifndef __IUPFILEDLG_H 
+#define __IUPFILEDLG_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* the only exported function, 
+   once called it will replace regular IupFileDlg */
+
+int IupNewFileDlgOpen(void);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif