Reference to field or property with explicit this in then block

Describe the bug

Making a reference to the spec's field or property using explicit-this in the then block produces an STC error. No error shows for this.myField in the when block.

this.myField in the then is written as $spock_valueRecorder.record($spock_valueRecorder.startRecordingValue(0), this).myField in the feature method. record returns Object, so as far as STC is concerned, it can't find the property "myField" in java.lang.Object.

Spock 2.4
Groovy 5.0.5

To Reproduce

@groovy.transform.TypeChecked
class SomeSpec extends Specification {
  String myField
  void testField() {
   when:
    this.myField = 'test'
   then:
    this.myField == 'test' // [Static type checking] - No such property: myField for class: java.lang.Object
  }
}

Expected behavior

this.myField checks properly or is exempted from STC in when, then, expect, etc.

Actual behavior

"[Static type checking] - No such property: myField for class: java.lang.Object"

Java version

Java 25.0.2

Buildtool version

Eclipse 2026-06 / Groovy 5.0.5

What operating system are you using

Windows

Start with the reproduced @TypeChecked specification in the issue and inspect how Spock transforms explicit this references in when and then blocks, especially the generated $spock_valueRecorder expression. Run the reproduction with Spock 2.4 and Groovy 5.0.5; done means the then-block reference no longer produces the reported STC error while the when-block behavior remains correct.