JDT is getting confused when coding inside a lambda

I'm using latest 2024-12 with JDK 21, to develop Mutiny's base code for Quarkus.

I'm getting problems with completion and compiler when coding inside a lambda. sometimes I need to copy and paste the code out of the lambda to get completion working...

```
return Uni.createFrom().item(() -> {

String jobName = getS <----- here I'm trying to do a space+bar to get the name of an existent method on the same class (but since the compiler identified that the code is broken it doesn't show anything.
}
```

Start by reproducing the reported completion and compiler behavior with the provided lambda snippet in JDT 2024-12 on JDK 21, comparing coding inside and outside the lambda. Done means completion can find the existing method inside the lambda and the compiler no longer treats the code as broken in this case.

Written by the indexing model from the issue text.