Apply the panel updates after stash operations in a single frame

Stashing and popping change both the stash list and the files list.
With each scope updating the UI as soon as its own refresh is done, the
two panels visibly change at different times; with
gui.shrinkSidePanelsToContent that also means their sizes change at
different times than their contents.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

pkg/gui/controllers/files_controller.go

@@ -1513,7 +1513,10 @@ func (self *FilesController) handleStashSave(stashFunc func(message string) erro
 			if err := stashFunc(stashComment); err != nil {
 				return err
 			}
-			self.c.Refresh(types.RefreshOptions{Scope: []types.RefreshableView{types.STASH, types.FILES}})
+			self.c.Refresh(types.RefreshOptions{
+				BatchUIUpdates: true,
+				Scope:          []types.RefreshableView{types.STASH, types.FILES},
+			})
 			return nil
 		},
 		AllowEmptyInput: true,

pkg/gui/controllers/stash_controller.go

@@ -199,7 +199,10 @@ func (self *StashController) postStashRefresh() {
 	// the remaining stash entries, and acting on the next entry in quick
 	// succession (confirming the popup and pressing the key again right away)
 	// must see the refreshed list, or it would target the wrong stash.
-	self.c.RefreshBlockingInput(types.RefreshOptions{Scope: []types.RefreshableView{types.STASH, types.FILES}})
+	self.c.RefreshBlockingInput(types.RefreshOptions{
+		BatchUIUpdates: true,
+		Scope:          []types.RefreshableView{types.STASH, types.FILES},
+	})
 }
 
 func (self *StashController) handleNewBranchOffStashEntry(stashEntry *models.StashEntry) error {