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

2025.03.07/02Ex/solve.c

@@ -0,0 +1,11 @@
+#include "solve.h"
+#include "math.h"
+
+double t2_solve(double *a, int n)
+{
+	double trace = 0;
+	int i;
+	for (i = 0; i < n; i++)
+		trace += a[i * n + i];
+	return trace;
+}