fix: add timeout to integration tests to prevent CI hangs

- Add timeout-minutes: 5 to docker-build.yml integration test step
- Add set -o pipefail to integration-test.sh
- Add 4-minute timeout wrapper (INTEGRATION_TEST_TIMEOUT env var)

Resolves hang after Caddy TLS cleanup in GitHub Actions run #20319807650

.github/workflows/docker-build.yml

@@ -294,6 +294,7 @@ jobs:
             -p 80:80 \
             ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ steps.tag.outputs.tag }}
       - name: Run Integration Test
+        timeout-minutes: 5
         run: ./scripts/integration-test.sh
 
       - name: Check container logs