Document CI/CD and improve pipeline feedback

Imported from GitHub pull request El-SaMa/oma#123 by @El-SaMa.

---

Summary

• Upload Playwright report/test-results artifacts when E2E fails in CI.
• Align scripts/ci-verify.sh with the GitHub Verify job (attribution tests, Enhance registry, optional migrate dry-run).
• Make staging deploy workflow_dispatch only until a host is wired (stops no-op runs after every main CI).
• Add admin handbook page Operations → CI and CD with draw.io overview + GitHub jobs diagrams; refresh the deployment pipeline diagram and cross-links.

Test plan

• Open /admin/docs/operations/ci-cd and confirm both diagrams render
• Open /admin/docs/operations/deployment and confirm updated diagram + CI/CD link
• Confirm handbook nav shows CI and CD under Operations (en/fi/sv titles)
• Optional: fail an E2E locally and confirm apps/web/playwright-report exists; on CI, confirm artifact upload step is present in ci.yml