Add governed-runner delegation map

[mdheller]

Summary

Adds the cross-repo governed-runner delegation map to the facade repo.

This records the boundary that prophet governed-runner ... and prophet agentplane ... are command-name facades only. Implementation remains delegated to AgentPlane's sp-run, while safety, authority, and install responsibilities remain in their owning repos.

Adds

• docs/governed-runner-delegation-map.md
• README pointer to the delegation map

Map covers

• prophet governed-runner <args> -> sp-run <args>
• prophet agentplane <args> -> sp-run <args>
• cross-repo ownership:
  • prophet-cli: product facade
  • agentplane: governed-runner implementation and sp-run
  • guardrail-fabric: safety/preflight semantics
  • agent-registry: authority state
  • homebrew-prophet: install path
• non-ownership list for prophet-cli
• hard non-goals for the facade
• regression rule: tests should assert forwarded argv, not duplicate AgentPlane behavior

Boundary

Documentation-only. No implementation moves into prophet-cli; no execution, mutation, rollback restore, authority update, budget settlement, provider invocation, or network activity is added.