docs(confidence-engine): verify findings derivation gap in production chain

Verified: deriveFindingsFromContributions() exists with passing tests but
is never called in production. The contributions → findings seam is un-wired:

1. handleDeconstructSubmit() sends contribution to ScenarioForm
2. appendFocusedContribution() stores it in focusedContributions[]
3. findings state stays [] — no derivation ever runs
4. empty findings sent to /api/cases/update (which only echoes them back)
5. nothing renders from the findings surface

Fix: call deriveFindingsFromContributions after contribution is appended.

components/scenario-form.jsx

@@ -5,6 +5,7 @@ import { useState, useRef, useMemo } from "react";
 import DiagnosticsView from "@/components/diagnostics-view";
 import ReasoningWorkspace, { LoadingOverlay, ContinueLaterBanner } from "@/components/reasoning-workspace";
 import { mockFetch, AVAILABLE_SCENARIOS } from "@/lib/mocks/confidence-engine/mock-client";
+import { deriveFindingsFromContributions, normalizeFindings } from "@/lib/graph/finding-helpers";
 
 /* Compile-time env resolution — NEXT_PUBLIC_ vars are injected by Next.js at build */
 const MOCK_ENABLED = process.env.NEXT_PUBLIC_CONFIDENCE_ENGINE_MOCKS === "true";