refactor(structure): normalize folder names with leading zeros for consistency

- Renamed all folders from format NEx (e.g., 1Ex, 2Ex...) to 0NEx (01Ex, 02Ex, etc.)
- Updated subdirectories and files accordingly
- Removed old main Makefile and tasks (a01.c–a09.c, solve.c, io_status.h), likely obsolete
- Cleaned up deprecated task binaries and configs

2025.02.28/07Ex/io_status.h

@@ -0,0 +1,14 @@
+#ifndef IO_STATUS_H
+#define IO_STATUS_H
+
+#define LEN 1234
+
+typedef enum _io_status
+{
+	SUCCESS,
+	ERROR_OPEN,
+	ERROR_READ,
+	ERROR_MEM
+} io_status;
+
+#endif