fix: override HOME=/home/runner in CI container options

GH Actions always sets HOME=/github/home (a mounted host temp dir)
regardless of Dockerfile USER. Bun uses HOME for temp/cache and can't
write to the GH-mounted dir. Override HOME to the actual runner home.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/workflows/evals.yml

@@ -62,7 +62,7 @@ jobs:
       credentials:
         username: ${{ github.actor }}
         password: ${{ secrets.GITHUB_TOKEN }}
-      options: --tmpfs /tmp:exec
+      options: --tmpfs /tmp:exec -e HOME=/home/runner
     timeout-minutes: 20
     strategy:
       fail-fast: false