Classify read-only wrappers with dynamic delegated effects

crates/objects/src/native.rs

@@ -55,6 +55,9 @@ impl CallArity {
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum CallEffect {
     ReadOnly,
+    /// The native body itself is read-only; delegated effects are dynamic and
+    /// checked by the VM in the same execution/heap scope.
+    Delegated,
     Mutating,
     External,
 }
@@ -192,7 +195,9 @@ impl CallSignature {
     ) -> Result<(), VmError> {
         self.validate(store)?;
         self.arity.check(name.into(), arguments.len())?;
-        if store.is_read_only() && self.effect != CallEffect::ReadOnly {
+        if store.is_read_only()
+            && !matches!(self.effect, CallEffect::ReadOnly | CallEffect::Delegated)
+        {
             return Err(VmError::InvalidArgument(
                 "native effect is forbidden during read-only execution",
             ));