Add Cockpit historic process instance delete

[hauptmedia]

Summary

• add a history process-instance delete API wrapper and state signal for POST /history/process-instance/delete
• add history-mode instance selection and confirmation controls in the process definition instances tab
• include delete reason, batch result link, i18n, CSS, and tests

Tests

• node -e "JSON.parse(require('fs').readFileSync('public/locales/en-US/translation.json','utf8')); JSON.parse(require('fs').readFileSync('public/locales/de-DE/translation.json','utf8'));"
• npx eslint src/pages/Processes.jsx src/pages/Processes.test.jsx src/api/resources/history.js src/api/resources/history.test.js src/state.js src/state.test.js
• npx vitest run src/api/resources/history.test.js src/state.test.js src/pages/Processes.test.jsx
• npx vitest run --maxWorkers=4
• npm run build
• Browser smoke: http://127.0.0.1:5176/processes/proc:1/instances?history=true reached the login boundary with no console errors

[sonarqubecloud]

Quality Gate passed

Issues
3 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud