Why: retain which CLI handled each task so routing can improve from real outcomes over time
Evidence: AgentExecHistoryTests and git diff --check
Impact: appends sanitized source-external JSONL records without changing run outcomes
Refs: feature/goal-first-delivery
Why: verify configured Agent CLIs one profile at a time before declaring them usable
Evidence: 53 focused tests, agent-exec validation, 397-test governance regression, and diff check
Impact: adds opt-in source-external probes, acceptance checks, and current task records
Refs: U5; docs/superpowers/plans/2026-10-15-project-agent-execution.md