fix(cicd): cover dependency install failure

[frobel0520]

Summary

• add a reachable npm ci failure scenario
• keep test, lint, build and artifact states not-run/missing after install failure
• allow required-check failure to reach the blocked terminal outcome
• update CI/CD acceptance contract and regression coverage

Verification

• npm --prefix frontend test -- src/topics/cicd/content.test.ts src/topics/cicd/simulator.test.ts src/topics/cicd/lab.test.ts src/topics/cicd/integration.test.ts
• npm --prefix frontend run lint