fix(unity/pesapi-v8): Reset value_persistent in pesapi_release_value_ref (#2342)

v8::Persistent uses NonCopyablePersistentTraits (kResetInDestructor == false), so the implicit ~pesapi_value_ref__() does not release the strong V8 global root. pesapi_release_value_ref freed the C++ struct but never Reset the persistent, so a JS function marshaled into a C# delegate (this path never calls pesapi_set_ref_weak, the persistent stays strong) and everything its closure captures leaked for the isolate lifetime. Affects native backends; WebGL (JS-mock ObjectPool) is unaffected. Add explicit value_persistent.Reset().

Author: hwei

unity/native/papi-v8/source/PesapiV8Impl.cpp

@@ -692,6 +692,11 @@ void pesapi_release_value_ref(pesapi_value_ref value_ref)
     {
         if (!value_ref->env_life_cycle_tracker.expired())
         {
+            // v8::Persistent uses NonCopyablePersistentTraits (kResetInDestructor == false),
+            // so ~pesapi_value_ref__() does NOT release the strong V8 global root. Without an
+            // explicit Reset(), a JS function marshaled into a C# delegate (this path never calls
+            // pesapi_set_ref_weak) and everything its closure captures leak for the isolate's lifetime.
+            value_ref->value_persistent.Reset();
             value_ref->~pesapi_value_ref__();
         }
         ::operator delete(static_cast<void*>(value_ref));