This change adds @sentry/nextjs to the project dependencies, pulling in the client, server, tracing, and build-time tooling needed to instrument a Next.js app. There’s no app-level configuration in this commit yet, but it lays the groundwork for capturing production errors, stack traces, and source-mapped issues once setup files are added. Practical effect: the repo is now ready for Sentry integration, but observability won’t change until the package is actually configured.