As the newly-hired senior C++ developer with GTK experience on the Inkscape project, you must navigate a complex mission to migrate the codebase to GTK4. Manage your team to implement the essential steps of the migration and stay ahead of the curve to avoid conflicts in other areas of the project. With expert knowledge of both the GTK framework and Inkscape's internal workings at your disposal, ensure a smooth transition to improve the performance of the user interface and canvas.