ci: add verification step to CI workflow

Runs `yarn verify` in CI to catch regressions in verified functions.
Only functions with `verified: X.Y` header are tested, ensuring CI
doesn't fail on unverified functions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: kvz

.github/workflows/ci.yml

@@ -44,6 +44,9 @@ jobs:
       - name: Test
         run: |
           corepack yarn test
+      - name: Verify against native runtimes
+        run: |
+          corepack yarn verify
       - name: Release
         if: startsWith(github.ref, 'refs/tags/')
         run: |