Surface workspace changes from agent panes (#3682)

* feat(app): refine workspace pane actions

Prioritize Changes when available, keep Files useful before a selection, and reserve desktop diff clicks for selection so comments require the explicit affordance. Move the Changes shortcut to Shift+G to avoid consuming a likely copy variant.

* feat(app): improve access to workspace changes

packages/app/src/git/diff-document/surface.web.tsx

@@ -495,7 +495,14 @@ export function DiffSurface(props: DiffSurfaceProps) {
         schedulePaint();
         return;
       }
-      if (drag && !moved && hit?.kind === "cell" && hit.target && reviewActions) {
+      if (
+        event.pointerType === "touch" &&
+        drag &&
+        !moved &&
+        hit?.kind === "cell" &&
+        hit.target &&
+        reviewActions
+      ) {
         selectionRef.current = null;
         reviewActions.onStartComment(hit.target);
         schedulePaint();