Encourage editing over re-creating a file from scratch (#29870)

I also introduced a new eval to prove the encouragement actually makes a
difference.

Release Notes:

- Improved agent behavior when streaming edits, encouraging it to
editing files as opposed to creating them from scratch

crates/eval/src/examples/mod.rs

@@ -13,6 +13,7 @@ use crate::example::{Example, ExampleContext, ExampleMetadata, JudgeAssertion};
 
 mod add_arg_to_trait_method;
 mod code_block_citations;
+mod comment_translation;
 mod file_search;
 mod planets;
 
@@ -22,6 +23,7 @@ pub fn all(examples_dir: &Path) -> Vec<Rc<dyn Example>> {
         Rc::new(add_arg_to_trait_method::AddArgToTraitMethod),
         Rc::new(code_block_citations::CodeBlockCitations),
         Rc::new(planets::Planets),
+        Rc::new(comment_translation::CommentTranslation),
     ];
 
     for example_path in list_declarative_examples(examples_dir).unwrap() {