RPI

Run one experiment from the caller's existing intent source through three responsibilities and stop:

anti-ceremony guard -> Plan -> Implement -> fresh Validate -> report

On CONTINUE, the core path remains Plan -> Implement -> fresh Validate -> report. RPI invokes the guard exactly once before Plan. It preserves the original intent and dispatches each core phase at most once. It does not own retries, budgets, queues, claims, leases, Git, delivery, release, closure, or the caller's next decision.

The pure scripts/run_once.py reference behavior makes the dispatch and stop semantics executable without Git, ao, or a tracker.

Admission and phase lock