Clarify CLI and Agent Skill legal terms

[AvdLee]

Summary

• Clarifies that RocketSim CLI and Agent Skill usage with authorized third-party tools is governed by those tools' own policies.
• Adds matching third-party responsibility language to the public terms page.
• Updates the visible revision dates on the terms and privacy pages.

Test plan

• npm run lint
• npm run format:check
• npm run typecheck
• npm run build
• npm run knip