feat(managed_agents): add multiagent and outcomes cookbooks

- CMA_coordinate_specialist_team.ipynb: heterogeneous team via the
  multiagent coordinator config — coordinator runs three specialists
  with scoped toolsets to assemble a sales proposal
- CMA_verify_with_outcome_grader.ipynb: grade-and-revise loop with
  Outcomes — writer drafts a cited brief, grader checks it against a
  rubric, feedback drives revisions until it passes; includes a
  rubric-writing section with failure modes and a six-principle table
- Update managed_agents/README.md and registry.yaml

Author: markn-ant