Server export conditions (`react-server`) resolve to the wrong branch

_Found running the official Next.js e2e test suite against vinext (vinext 1.0.0-beta.8, Next.js 16.2). Error line is from the suite's own output._

**Fixture:** `test/e2e/import-conditions`

**Symptom:** `serverFavoringBrowser` / `react-server` export conditions resolve to the wrong branch in the server bundle.

**Repro:** a dependency whose `exports` map differentiates a `react-server` condition; assert the server build selects the `react-server` entry.

Start with the `test/e2e/import-conditions` fixture and reproduce the issue by running the official Next.js e2e test suite against vinext. Check how the server bundle handles a dependency whose `exports` map includes a `react-server` condition; done means the server build selects that entry.

Written by the indexing model from the issue text.