Expose chunk plan provenance and safe diagnostics

internal/modules/generic/chunk/units/chunker.go

@@ -38,6 +38,10 @@ func (c *Chunker) Key() string {
 	return Key
 }
 
+func (*Chunker) ExecutionClass() contracts.ExecutionClass {
+	return contracts.ExecutionClassDeterministic
+}
+
 func (c *Chunker) ReferenceSlots() []contracts.ReferenceSlot {
 	return nil
 }