Patch setHeader for direct route handlers (#93101)
## Summary
- apply the `setHeader` cookie-support patch to direct route module
handlers in `prepare()`
- make `patchSetHeaderWithCookieSupport()` idempotent so both entry
paths can call it safely
- add an adapter-like direct RSC regression test that fails without the
patch
Closes: NEXT-4919
## Testing
- `NEXT_SKIP_ISOLATE=1 NEXT_TEST_MODE=start pnpm testheadless
test/e2e/app-dir/cache-components/cache-components.test.ts -t "should
ignore late setHeader calls for direct RSC handlers after headers are
sent"`
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