Architecture: after successful /api/cases/update, derive explicit nextGraph +
nextFindings, call synthesizeFromFindings exactly once, replace Current
Understanding with reconstruction result.
Key invariants:
- outcome.summary retired as final CU authority → always synthesis reconstruction
- Explicit derived state (no React-state reread) for graph and findings
- Previous CU preserved on synthesis failure (no fallback to outcome.summary)
- Graph and Findings NOT lost on synthesis failure
- saveInvestigation persistence uses currentUnderstanding, not outcome.summary
Deterministic regression: 7 tests (Cases A-E + 2 edges) covering all rules.
Files: components/scenario-form.jsx, tests/ui/scenario-form-case-update-synthesis.test.jsx
robbond
b270aa5624