Mission Run Overview
Mission Run: Fix plan-mission guard/manifest artifact-vocabulary mismatch
Let a built-in plan mission advance past specify by reconciling the plan family's expected-artifacts manifest with the artifacts its step contracts and guards actually use.
On main (4.0.0rc8) a built-in plan mission is hard-blocked at specify: next reports 'Required artifact missing: spec.md' even with spec.md committed, and guard_failure_paths is empty (#6388, P0). The plan guard chain checks spec.md/research.md/plan.md (what the step contracts actually produce) but the plan expected-artifacts.yaml manifest declares goals.md under phase step-keys goals/draft, so the presence gatherer never looks for spec.md and required_artifacts_for returns nothing. This mission reconciles the manifest (and the descriptive mission.yaml copies) to the runtime action vocabulary, restores guard_failure_paths, and adds the parity + completeness guards that would have caught the drift.