Read searchParams in blog and docs fixture pages for deploy-mode search reporting
Same fix as /query and /rewrite-target: a page that ignores searchParams serves
a shared static prerender when deployed, so its renderedSearch — and the
transition event's searchParams — comes back empty. The blog/[slug] and
docs/[...parts] pages passed in next start (dynamic-param routes render
per-request there) but failed deployed. Read searchParams so the render varies
on them in every delivery mode, and overlay 'instant = false' under cache
components (dynamic access outside Suspense).