Next.js Performance Profiler & Automated Fix Suggester

/next-devtools- exposes Next.js build metrics, route performance data, and component tree diagnostics; chrome-devtools- captures live browser runtime profiles (LCP, CLS, JS execution traces) for the running app; /-code-interpreter analyses the combined build + runtime data to identify the specific components and routes causing performance regressions, then generates prioritised fix recommendations with code snippets. Together they close the loop from 'my Next.js app is slow' to 'here is the exact fix'.