fix: target caret excerpts and retain diff viewport offsets

src/session.rs

@@ -258,6 +258,17 @@ impl EditorSession {
         &self.editor
     }
 
+    pub(crate) fn set_diff_viewport(
+        &mut self,
+        comparison_id: u64,
+        file: usize,
+        top: usize,
+        left_after: usize,
+    ) {
+        self.editor
+            .set_diff_viewport(comparison_id, file, top, left_after);
+    }
+
     pub(crate) fn scroll_diff(&mut self, focus: Focus, down: bool) {
         self.editor.scroll_diff(focus, down);
     }