Add copying utility methods to Arena

tests/test_metric.cpp

@@ -585,32 +585,6 @@ TEST_CASE("thread counter cleanup bug") {
   }
 }
 
-TEST_CASE("error conditions") {
-  SUBCASE("counter negative increment") {
-    auto counter_family = metric::create_counter("error_counter", "Error test");
-    auto counter = counter_family.create({});
-
-    // This should abort in debug builds due to validation
-    // In release builds, behavior is undefined
-    // counter.inc(-1.0); // Would abort
-  }
-
-  SUBCASE("invalid metric names") {
-    // These should abort due to validation
-    // auto bad_counter = metric::create_counter("123invalid", "help"); // Would
-    // abort auto bad_gauge = metric::create_gauge("invalid-name", "help");   //
-    // Would abort
-  }
-
-  SUBCASE("invalid label keys") {
-    auto counter_family = metric::create_counter("valid_name", "help");
-
-    // This should abort due to label validation
-    // auto counter = counter_family.create({{"123invalid", "value"}}); // Would
-    // abort
-  }
-}
-
 TEST_CASE("memory management") {
   SUBCASE("arena allocation in render") {
     Arena arena;