next.js

5b0497df - Serve in-memory __next_error__ HTML for App Router errors in dev mode

Serve in-memory __next_error__ HTML for App Router errors in dev mode For App Router routes in dev mode, render errors using an in-memory HTML shell that bootstraps the client-side dev overlay instead of going through the Pages Router _error/_app/_document rendering pipeline. This avoids spawning pagesErrorEndpoint in Turbopack for app-router-only projects, which was causing task conflicts when multiple pages tried to write the same route. - Add buildAppRouterDevErrorHtml() helper that constructs a minimal HTML shell with the __next_error__ id pattern - Short-circuit renderErrorToResponseImpl for app router errors - Guard ensurePage('/_error') in turbopack hot reloader for app-only projects - Skip getFallbackErrorComponents for app-only projects - Tag error requests with isAppRouteError meta for mixed app+pages projects Co-Authored-By: Claude <noreply@anthropic.com>