fix: copy locales and templates for e2e-tests GitHub Actions workflow

The e2e-tests workflow was failing because the application couldn't find
the locales/en.json and templates files. These files are in backend/locales
and backend/templates, but the standalone binary expects them at the root.

This commit adds a step to copy these directories before starting the server.

.github/workflows/e2e-tests.yml

@@ -75,6 +75,11 @@ jobs:
             echo "test_private_key_base64_encoded_here" > /tmp/ed25519.key
           fi
 
+      - name: Copy locales and templates
+        run: |
+          cp -r backend/locales .
+          cp -r backend/templates .
+
       - name: Start Ackify server
         env:
           ACKIFY_DB_DSN: "postgres://postgres:testpassword@localhost:5432/ackify_test?sslmode=disable"