improve: show whole-diff totals alongside file stats

tests/unit/editor.rs

@@ -1887,6 +1887,7 @@ fn hidden_tab_diff_results_restore_visible_insert_interaction_and_route_request_
             editable_paths: Default::default(),
             files: vec![ChangedFile {
                 review_revisions: None,
+                stats: None,
                 loaded: true,
                 path: "file.txt".into(),
                 old_path: None,
@@ -3053,6 +3054,7 @@ fn working_diff(editor: &mut Editor, root: &Path, paths: &[&str]) -> Box<[(PathB
             let lines: Vec<String> = text.lines().map(str::to_owned).collect();
             ChangedFile {
                 review_revisions: None,
+                stats: None,
                 loaded: true,
                 path: PathBuf::from(*path),
                 old_path: None,
@@ -3115,6 +3117,7 @@ fn historical_diff(editor: &mut Editor, root: &Path, before: Vec<String>, after:
             editable_paths: Default::default(),
             files: vec![ChangedFile {
                 review_revisions: None,
+                stats: None,
                 loaded: true,
                 path: "file.txt".into(),
                 old_path: None,
@@ -4078,6 +4081,7 @@ fn bookmark_refresh_reloads_paths_and_preserves_view_until_lazy_content_arrives(
     let cursor = editor.cursor();
     let file = |path: &str, loaded| ChangedFile {
         review_revisions: None,
+        stats: None,
         path: path.into(),
         old_path: None,
         status: FileStatus::Modified,
@@ -4288,6 +4292,7 @@ fn completed_working_refresh_serializes_lazy_selection_and_invalidates_pending_n
         if changed {
             let file = crate::diff::ChangedFile {
                 review_revisions: None,
+                stats: None,
                 path: "nested/new.txt".into(),
                 old_path: Some("nested/old.txt".into()),
                 status: crate::diff::FileStatus::Renamed,
@@ -4329,6 +4334,7 @@ fn lazy_lsp_target(editor: &mut Editor) -> crate::diff::ChangedFile {
     let comparison = diff.comparison.as_mut().unwrap();
     comparison.files.push(ChangedFile {
         review_revisions: None,
+        stats: None,
         path: "nested/new.txt".into(),
         old_path: Some("nested/old.txt".into()),
         status: FileStatus::Renamed,
@@ -4350,6 +4356,7 @@ fn lazy_lsp_target(editor: &mut Editor) -> crate::diff::ChangedFile {
     ));
     ChangedFile {
         review_revisions: None,
+        stats: None,
         path: "nested/new.txt".into(),
         old_path: Some("nested/old.txt".into()),
         status: FileStatus::Renamed,