feat(vcs): soft-wrap long lines in the diff viewer (#2286)

The diff viewer never soft-wrapped, so a long changed line ran off the right edge. Diff panes now follow Settings › Editor › General › Soft-wrap files for the file, and the viewer's settings menu has a Use Soft Wraps checkbox that overrides it for all diffs and is remembered with the other viewer options. View › Active Editor › Soft-Wrap (editor.toggleSoftWrap) also toggles it when a diff pane has focus. Toggling reconfigures both panes in place, keeping the selection and the scroll position, including aligned split diffs.

Closes #2263

Co-authored-by: atlas-u <[email protected]>

src-tauri/src/menu.rs

@@ -395,6 +395,7 @@ pub fn spec(os: Os) -> Vec<Entry> {
                     sub("statusBarWidgets", "Status Bar Widgets", vec![Entry::Dynamic(DYNAMIC_STATUS_BAR_WIDGETS)]),
                 ],
             ),
+            sub("activeEditor", "Active Editor", vec![act("editor.toggleSoftWrap", "Soft-Wrap")]),
             SEP,
             act("code.quickDefinition", "Quick Definition"),
             act("code.quickTypeDefinition", "Quick Type Definition"),
@@ -1652,6 +1653,24 @@ mod tests {
         }
     }
 
+    #[test]
+    fn soft_wrap_is_available_under_view_active_editor_on_every_os() {
+        for os in ALL_OS {
+            let menus = spec(os);
+            let Entry::Submenu { children: view, .. } =
+                menus.iter().find(|e| matches!(e, Entry::Submenu { id: "view", .. })).unwrap()
+            else {
+                panic!("View menu missing")
+            };
+            let Entry::Submenu { children: active, .. } =
+                view.iter().find(|e| matches!(e, Entry::Submenu { id: "activeEditor", .. })).unwrap()
+            else {
+                panic!("Active Editor menu missing")
+            };
+            assert!(action_ids(active).contains(&"editor.toggleSoftWrap"), "{os:?}");
+        }
+    }
+
     #[test]
     fn unchanged_menu_config_is_not_rebuilt() {
         let state = MenuState::default();