Turbopack's Memory Crisis: A Surgical Fix for Cache-Path Watchers

High CPU and memory usage in Next.js Turbopack's dev server significantly hampers local development workflows. This targeted fix addresses a specific boundary issue: filesystem watchers were treating cached and generated-path changes as source modifications, triggering unnecessary invalidation cycles. By filtering these non-source paths from the watcher pipeline, Turbopack can focus computational resources on actual source changes, delivering faster local development.