Verified: npm run typecheck clean, eslint clean on all three files. Not verified: the actual clicks — no browser here. Worth 30 seconds of your time to confirm View ↗ on Test Article 1 testing still opens the public page rather than the editor, since that's the one interaction the guard has to get right.
I did not run npm run build — your dev server is up, and building while it holds .next is what caused the all-routes-404 last time. Stop dev and