ci: fix host-cpp-tests label check to match the actual "Host 🏡" label

The job checked for a label literally named "host", but the repository's
real label (used on issues, e.g. #428/#420/#412) is "Host 🏡" — a label
named plain "host" existed too, seemingly a leftover/duplicate, and has
since been deleted. The condition never actually matched the label anyone
would apply in practice, so this job only ever ran on pushes to main/next,
never on a labeled PR.

Found while attaching labels to this PR: the CI still showed green with
host-cpp-tests silently not running, exactly the kind of gap
.claude/CLAUDE.md (#436) exists to prevent.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DaK9eAAF5G8wj6UT8VekAm

Author: claude

.github/workflows/check.yml

@@ -154,7 +154,7 @@ jobs:
           ctest --test-dir build --output-on-failure
         working-directory: packages/weak-node-api
   host-cpp-tests:
-    if: github.ref == 'refs/heads/main' || github.ref == 'refs/heads/next' || contains(github.event.pull_request.labels.*.name, 'host')
+    if: github.ref == 'refs/heads/main' || github.ref == 'refs/heads/next' || contains(github.event.pull_request.labels.*.name, 'Host 🏡')
     strategy:
       fail-fast: false
       matrix: