ep: Fix teacher parser and other fixes (#49863)

Release Notes:

- N/A

crates/edit_prediction_cli/evals/flask--add-and-rename-test-function.md

@@ -78,3 +78,21 @@ def test_static_url_path():
 +    assert rv.status_code == 404
 +    rv.close()
 ```
+
+```diff
+--- a/tests/test_basic.py
++++ b/tests/test_basic.py
+@@ -1376,8 +1376,13 @@
+-def test_static_file_not_found():
+-    pass
++def test_static_file_not_found(app, client):
++    rv = client.get("/static/nonexistent.html")
++    assert rv.status_code == 404
++    assert rv.data.strip() == b"<h1>Not Found</h1>"
++    with app.test_request_context():
++        pytest.raises(BuildError, flask.url_for, "static", filename="nonexistent.html")
++    rv.close()
+
+
+ def test_static_url_path():
+```

crates/edit_prediction_cli/evals/tree-sitter--tuple-to-struct-destructuring.md

@@ -138,7 +138,7 @@ revision = "24007727d42b4caceda3095ac685c463fae1ba1a"
 
      fn language_for_id(&self, id: usize) -> LoaderResult<Language> {
 -        let (path, language, externals) = &self.languages_by_id[id];
-+        let LanguageEntry { path, language, external_files } = &self.languages_by_id[id];
++        let LanguageEntry { path, language, external_files  } = &self.languages_by_id[id];
          language
              .get_or_try_init(|| {
                  let src_path = path.join("src");

crates/edit_prediction_cli/src/format_prompt.rs

@@ -211,12 +211,17 @@ impl TeacherPrompt {
 
     pub fn parse(example: &Example, response: &str) -> Result<(String, Option<ActualCursor>)> {
         // Check if the model indicated no edits are needed
+        let no_edits = (String::new(), None);
         if let Some(last_codeblock) = extract_last_codeblock(&response) {
             if last_codeblock.trim() == Self::NO_EDITS {
-                return Ok((String::new(), None));
+                return Ok(no_edits);
             }
         }
 
+        if response.trim().ends_with(Self::NO_EDITS) {
+            return Ok(no_edits);
+        }
+
         // Extract updated (new) editable region from the model response.
         let new_editable_region = Self::extract_editable_region(&response)?;
         let cursor_offset = new_editable_region.find(Self::USER_CURSOR_MARKER);

crates/edit_prediction_cli/src/repair.rs

@@ -79,7 +79,7 @@ pub struct RepairArgs {
 
 fn model_for_backend(backend: BatchProvider) -> &'static str {
     match backend {
-        BatchProvider::Anthropic => "claude-sonnet-4-5",
+        BatchProvider::Anthropic => "claude-sonnet-4-6",
         BatchProvider::Openai => "gpt-5.2",
     }
 }