Add delegated connector executor with no-key verification paths

[jmcentire]

Summary

• add a delegated connector executor with scoped verification, ordered failover, circuit health, idempotency, and sanitized monitoring events
• replace static control authorization and certificate private-material test paths with injected decision/reload outcomes
• make documented verification run the source checkout through configurable python3 defaults

Verification

• statically classified executable test/deploy credential candidates after the changes; no credential/key-value or private-material construction candidates remain
• make test lint (1085 passed; source compilation passed)

Boundary

• this does not implement a concrete secret-store resolver or trusted capability-verifier binding
• this does not migrate MEA comms away from its existing direct sender paths; that remains gated on integration review and custody wiring

[jmcentire]

Executor ownership overlap was identified during MEA/Claude reconciliation. This PR is intentionally draft pending a decision on whether the Baton orchestration primitive should be adopted into Claude's executor lane or closed. Independent no-key/control/certificate/verification changes have been split to #14.

[jmcentire]

Updated after #14 merged: current main has been merged into this draft branch and make test lint passes (1085 passed). The PR diff is now intended to contain only the optional delegated connector orchestration primitive and its injected-outcome tests for Claude's adopt-or-close decision.

[jmcentire]

Closing as superseded by #17. PR #17 contains and reconciles the delegated connector executor scope, is rebased onto current main, and remains the only draft that should proceed through review.