GCC does not provide std::ceil/std::find through these transitive includes.
Include their standard headers explicitly; no test or application logic changes.

--- a/tests/ui/test_dialog.cpp
+++ b/tests/ui/test_dialog.cpp
@@ -7,6 +7,7 @@
 #include "ui/controls.h"
 #include "ui/datetime.h"
 #include "base/time.h"
+#include <cmath>
 
 using namespace uitest;
 
--- a/tests/app/claude/test_links.cpp
+++ b/tests/app/claude/test_links.cpp
@@ -14,6 +14,7 @@
 #include "plat/plat.h"
 #include "support/test.h"
 
+#include <algorithm>
 #include <cstdio>
 #include <functional>
 #include <memory>