Now the browser back button will work correctly: (#820)

- Navigate to task sidebar → browser history has projects page + task sidebar
- Toggle to fullscreen → browser history has projects page + task sidebar + task fullscreen
- Click browser back → returns to task sidebar
- Click browser back again → returns to projects page

This preserves the expected browser navigation behavior while maintaining the fullscreen toggle functionality.

frontend/src/hooks/useTaskViewManager.ts

@@ -33,7 +33,7 @@ export function useTaskViewManager() {
           : currentPath;
       }
 
-      navigate(targetPath, { replace: true });
+      navigate(targetPath);
     },
     [location.pathname, navigate]
   );