Add compile-tests step to GitHub Actions CI workflow

The test-ci script loads pre-compiled test files from test/compiled/,
but this directory is in .gitignore. Add explicit compile-tests step
in the CI workflow to generate these files before running tests.

This ensures the compiled test files exist in the CI environment.

Author: claude

.github/workflows/continuous-integration.yml

@@ -18,6 +18,8 @@ jobs:
         run: npm ci
       - name: Build
         run: npm run build
+      - name: Compile tests
+        run: npm run compile-tests
       - name: Run tests
         run: npm run test-ci