fix: PDF tests data file loading and Chrome installation in CI

- Add findDataFile() helper to search up directory tree for data files
- Fixes tests running from subdirectories (internal/handlers)
- Install Chrome in GitHub Actions for PDF generation tests

This resolves test failures that have existed since PDF tests were introduced:
- Error: 'open data/cv-es.json: no such file or directory'
- Error: 'chrome failed to start'

Tests now properly locate data files from any working directory and
have Chrome available for PDF generation in CI environment.

.github/workflows/test.yml

@@ -30,6 +30,13 @@ jobs:
       - name: Verify dependencies
         run: go mod verify
 
+      - name: Install Chrome for PDF tests
+        run: |
+          wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -
+          sudo sh -c 'echo "deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google-chrome.list'
+          sudo apt-get update
+          sudo apt-get install -y google-chrome-stable
+
       - name: Run linter
         uses: golangci/golangci-lint-action@v7
         with: