Update includes in test_param_prob.h to use atoms/ prefix

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Transurgeon

tests/problem/test_param_prob.h

@@ -5,9 +5,8 @@
 #include <stdio.h>
 #include <string.h>
 
-#include "affine.h"
-#include "bivariate.h"
-#include "elementwise_restricted_dom.h"
+#include "atoms/affine.h"
+#include "atoms/elementwise_restricted_dom.h"
 #include "expr.h"
 #include "minunit.h"
 #include "problem.h"