Experiment 45 — passive boundary experiment measuring the existing
assessor's too_broad threshold from two to five competing unknowns.
Key findings:
- Boundary switches exactly between three and four active unknowns
- Clarify eligibility follows the same boundary
- Resolved-item gate works correctly (1 stays too_broad, 2 clears it)
- 2–3 unknowns return cannot_determine health (not healthy or too_broad)
- Boundary appears mechanically clear but conceptually uncertain
No production code changed. Synthetic fixtures only.
