修复

core/tests/compile_fail/duplicate_attribute.cpp

@@ -0,0 +1,10 @@
+#include <structive/property/property.hpp>
+struct Device { int value{}; };
+int main() {
+    auto schema = structive::object<Device>(
+        structive::field<&Device::value>(
+            structive::key<"value">,
+            structive::unit<"first">,
+            structive::unit<"second">));
+    static_cast<void>(schema);
+}