experiment: audit behaviour reachability and blocking

docs/current-project-state.md

@@ -75,7 +75,7 @@ The following were built during Experiments 18–25B. They are isolated diagnost
 
 ## 6. Work Currently Paused
 
-- Engine experiments are at Experiment 39 (passive Behaviour Selection validation, awaiting review);
+- Engine experiments are at Experiment 40 (behaviour reachability diagnostic — no rule changes).
 - UI experiments are paused;
 - Knowledge-management experiments are complete (confirmed by Experiment 38 cold-start validation);
 - Nothing historical has been deleted or archived yet.
@@ -100,7 +100,7 @@ Historical documents are retained under `docs/archive/` and should be opened onl
 
 ## 8. Return-to-Work Summary
 
-Engine experiments advanced to Experiment 39, a passive validation of Behaviour Selection against real Investigation State Assessment outputs. The existing selector produces all valid behaviours but Acknowledge dominates (71%) because it fires first when health=healthy. No user-facing engine behaviour changed. Knowledge-management phase is complete: all seven criteria met. No backlog items deleted or promoted.
+Engine experiments advanced to Experiment 40, a reachability diagnostic confirming Summarise and Pause fire their rules but are always blocked by Acknowledge (priority-1 conflict), while Clarive's triggers never activate in tested scenarios due to narrow `too_broad` health conditions. All five behaviours confirmed independently reachable synthetically. No rules or engine behaviour changed. Knowledge-management phase is complete: all seven criteria met. No backlog items deleted or promoted.
 
 First document to read: `docs/current-project-state.md`. Then consult `.claude/architecture-guardrails.md` before any code changes and `docs/project-knowledge-inventory.md` for task-specific references. The full experiment history remains available in `docs/design-evolution-log.md` but is no longer default reading.