Add Cockpit cleanup view

[hauptmedia]

Summary

• add a Cockpit Cleanup page at /cleanup for Camunda 7 Enterprise-style history cleanup operations
• wire cleanup REST resources for configuration, jobs, cleanable reports, removal metrics, TTL updates, and immediate cleanup trigger
• add navigation, state signals, translations, styles, and tests

Verification

• npx eslint src/api/resources/cleanup.js src/api/resources/cleanup.test.js src/pages/Cleanup.jsx src/pages/Cleanup.test.jsx src/api/engine_rest.jsx src/components/GoTo.jsx src/components/GoTo.test.jsx src/components/Header.jsx src/index.jsx src/state.js src/state.test.js
• npx vitest run src/api/resources/cleanup.test.js src/pages/Cleanup.test.jsx src/state.test.js src/components/GoTo.test.jsx src/components/Header.test.jsx
• npx vitest run
• npm run build
• Browser smoke: /cleanup loads the login boundary without console errors; authenticated cleanup page requires a running backend accepting the dev login

[sonarqubecloud]

Quality Gate failed

Failed conditions
7.6% Duplication on New Code (required ≤ 3%)

See analysis details on SonarQube Cloud