Core Changes

• [test] Enable reactDebugChannel for experimental test shards: #84533
• Simplify Metadata components: #84527
• Implement the updated prerender API shape: #84254
• Upgrade React from 85c427d8-20251003 to 4fdf7cf2-20251003: #84499
• Upgrade React from 4fdf7cf2-20251003 to c7862584-20251006: #84573
• fix(Turbopack): Add better error messaging for when we can't determine Next.js root: #83918

Misc Changes

• next mcp router
• Revert "next mcp router"
• test: Use nextTestSetup in scss tests: #84501
• [turbopack[ Use the configured hasher to implementh Hash for AutoMap and AutoSet: #84542
• Turbopack: debug ids for server chunks: #84557
• CI: Enable experimental.isolatedDevBuild for test-unit: #84559
• [test]: convert prefetching tests to be segmentCache compatible: #84521
• CI: Enable experimental.isolatedDevBuild for test-prod: #84556
• Add .next/dev/types to CNA templates tsconfig include: #84566
• CI: Enable experimental.isolatedDevBuild for test-integration: #84558
• Update Rspack development test manifest: #84548
• Add a webpack flag to create next app. Ensure that if you set it or decline turbopack we set the --webpack flag on the generated project: #84476
• Update Rspack production test manifest: #84549

Credits

Huge thanks to @unstubbable, @gnoff, @bgw, @lukesandberg, @mischnic, @devjiwonchoi, @ztanner, @Cy-Tek, and @vercel-release-bot for helping!