Context: PR #2193 exists on the JSS repo to upgrade Next.js to 16.2. Next.js 16.2 includes security hardening against CVE-2026-23864 fallout, ~400% faster dev startup via Turbopack improvements, and the hydration diff indicator for debugging. The current peer dependency `^16.1.0` already covers 16.2, so this is primarily a dev/test dependency update and verification pass. Keeping JSS aligned with Content SDK's Next.js version reduces friction for teams running both side-by-side during migration.
Steps:
1. Review PR #2193 for completeness (verify all `package.json` files updated, no stale lockfile entries)
2. Run the full test suite: `yarn test-packages`
3. Verify `next dev` and `next build` work with Turbopack (the new default in 16.2)
4. Merge PR #2193
5. Update CHANGELOG
Acceptance criteria:
Next.js 16.2 installed across all relevant packages
Full test suite passes
Turbopack dev/build verified
CHANGELOG updated
Risks: Turbopack becoming the default bundler in 16.2 could surface issues with JSS's custom webpack plugins or loaders. If Turbopack issues arise, document them as known issues rather than investing in fixes for a winding-down SDK.