Update next build --debug-build-paths so selective builds support App Router metadata routes. The selected App Router files should follow the same route-file semantics as a normal App Router build, including dynamic metadata files such as robots and sitemap routes and the project's configured page extensions. Selecting metadata files must build their public routes without pulling unrelated routes into the build. Preserve selective building for ordinary App Router pages and route handlers, Pages Router routes, and the existing path, glob, negation, and src/ input forms.