* fix(app-router): match Next.js RSC Content-Type (no charset suffix)
Next.js sets the RSC (React Server Components / 'flight') response
Content-Type to exactly 'text/x-component' (RSC_CONTENT_TYPE_HEADER in
.nextjs-ref/packages/next/src/client/components/app-router-headers.ts:17,
used by FlightRenderResult in
.nextjs-ref/packages/next/src/server/app-render/flight-render-result.ts:15).
vinext was sending 'text/x-component; charset=utf-8'. The suffix breaks
Next.js's own segment-cache deduplication checks (action-handler.ts uses
.startsWith(RSC_CONTENT_TYPE_HEADER) on the unsuffixed string) and fails
Next.js e2e tests that assert strict equality, e.g.:
- test/e2e/app-dir/app/index.test.ts L362, L371
- test/e2e/app-dir/segment-cache/deployment-skew/deployment-skew.test.ts L80
Replace the duplicated literal at seven sites with the existing
VINEXT_RSC_CONTENT_TYPE constant in app-rsc-cache-busting.ts.
* fix(app-router): match Next.js 404 plain-text body 'This page could not be found'
Next.js's plain-text 404 response body is exactly
'This page could not be found' (no trailing period in the response body;
the React-rendered not-found component uses the same text with a period).
vinext was returning 'Not Found' / '404 Not Found' / '404 - Not found',
which fails Next.js e2e tests that assert .toContain('This page could
not be found'), e.g.:
- test/e2e/app-dir/app/index.test.ts (several cases)
- test/e2e/app-dir/parallel-route-not-found/parallel-route-not-found.test.ts L52
- test/e2e/app-dir/prefetching-not-found/prefetching-not-found.test.ts L16
Next.js source citations (in .nextjs-ref):
- packages/next/src/server/route-modules/pages/pages-handler.ts L121, L535
- packages/next/src/build/templates/app-route.ts L170, L349
- packages/next/src/build/templates/app-page.ts L701, L1043
- packages/next/src/pages/_error.tsx L7
- packages/next/src/client/components/builtin/not-found.tsx L7 (HTML variant)
Updates the body in notFoundResponse() and the open-redirect / pages-router
SSR-fallback / worker-entry inline 404 sites. The HTTP status reason phrase
('Not Found') is unchanged. Route-specific bodies like '404 - API route not
found' are intentionally retained.