Rewrite the guide in short factual prose aligned with actual CrewAI
behavior: kickoff vs Task/Crew controls, Agent.guardrail kickoff-only,
global CrewBase hooks, tool HookAborted scope, fail-open hooks, and
memory fallback. Add ar/ko/pt-BR pages and nav entries.
Co-authored-by: Rip&Tear <theCyberTech@users.noreply.github.com>