Feat: script execution performance optimization

src/model/script.rs

@@ -11,12 +11,12 @@ impl ScriptEngine {
         }
     }
 
-    pub fn evaluate(&self, script: &str, ctx: &StepContext) -> Result<Vec<String>, String> {
+    pub fn evaluate(&mut self, script: &str, ctx: &StepContext) -> Result<Vec<String>, String> {
         self.forth.evaluate(script, ctx)
     }
 
     pub fn evaluate_with_trace(
-        &self,
+        &mut self,
         script: &str,
         ctx: &StepContext,
         trace: &mut ExecutionTrace,