feat: surface answer impact after update

components/reasoning-workspace.jsx

@@ -250,6 +250,89 @@ function LoadingOverlay({ isLoading, elapsed, currentMessage, variant }) {
   );
 }
 
+// ── Update acknowledgement ────────────────────────────────────
+function UpdateAcknowledgement({ answer, updateResult }) {
+  if (!updateResult || !answer?.trim()) return null;
+
+  const hasResolvedNodes =
+    updateResult.resolvedUnknownNodeIds && updateResult.resolvedUnknownNodeIds.length > 0;
+  const hasAffectedNodes =
+    updateResult.affectedNodeIds && updateResult.affectedNodeIds.length > 0;
+  const graph = updateResult.updatedSituationGraph;
+
+  function getNodeText(nodeId) {
+    if (!graph?.nodes) return String(nodeId);
+    const node = graph.nodes.find((n) => n.id === nodeId);
+    if (node) {
+      const parts = [node.label];
+      if (node.status !== "resolved") {
+        parts.push(node.status);
+      }
+      return parts.join(" ");
+    }
+    return String(nodeId);
+  }
+
+  let changedText;
+  if (hasResolvedNodes || hasAffectedNodes) {
+    const items = [];
+    if (hasResolvedNodes) {
+      for (const id of updateResult.resolvedUnknownNodeIds.slice(0, 5)) {
+        items.push(getNodeText(id));
+      }
+      if (updateResult.resolvedUnknownNodeIds.length > 5) {
+        items.push(`and ${updateResult.resolvedUnknownNodeIds.length - 5} more resolved`);
+      }
+    }
+    if (hasAffectedNodes && !hasResolvedNodes) {
+      for (const id of updateResult.affectedNodeIds.slice(0, 5)) {
+        items.push(getNodeText(id));
+      }
+      if (updateResult.affectedNodeIds.length > 5) {
+        items.push(`and ${updateResult.affectedNodeIds.length - 5} more affected`);
+      }
+    }
+    if (items.length === 0 && updateResult.changesApplied) {
+      const parts = [];
+      const ca = updateResult.changesApplied;
+      if (ca.addedNodeCount) parts.push(`${ca.addedNodeCount} node(s) added`);
+      if (ca.updatedNodeCount) parts.push(`${ca.updatedNodeCount} node(s) updated`);
+      if (ca.resolvedUnknownCount) parts.push(`${ca.resolvedUnknownCount} unknown(s) resolved`);
+      changedText = parts.join(", ");
+    } else {
+      changedText = items.join(". ") + ".";
+    }
+  } else if (updateResult.changesApplied) {
+    const ca = updateResult.changesApplied;
+    const parts = [];
+    if (ca.addedNodeCount) parts.push(`${ca.addedNodeCount} node(s) added`);
+    if (ca.updatedNodeCount) parts.push(`${ca.updatedNodeCount} node(s) updated`);
+    if (ca.addedEdgeCount) parts.push(`${ca.addedEdgeCount} edge(s) added`);
+    if (ca.removedEdgeCount) parts.push(`${ca.removedEdgeCount} edge(s) removed`);
+    changedText = parts.length > 0 ? parts.join(", ") : null;
+  }
+
+  const summary = updateResult.summary || null;
+  const displayChanged = summary || changedText || "Your answer has been added to the investigation.";
+
+  return (
+    <div className="rounded-lg border border-blue-200 bg-blue-50 px-5 py-4 space-y-3">
+      <div>
+        <h3 className="mb-1 text-xs font-medium uppercase tracking-wide text-blue-700">
+          You told us
+        </h3>
+        <p className="text-sm leading-relaxed text-blue-900">{answer}</p>
+      </div>
+      <div>
+        <h3 className="mb-1 text-xs font-medium uppercase tracking-wide text-blue-700">
+          What changed
+        </h3>
+        <p className="text-sm leading-relaxed text-blue-900">{displayChanged}</p>
+      </div>
+    </div>
+  );
+}
+
 // ── Developer details disclosure ──────────────────────────────
 function DeveloperDetails({ graph, selectedQuestion, diagnostics, newlySurfacedNodeIds, updateResult }) {
   return (
@@ -340,11 +423,16 @@ export default function ReasoningWorkspace({
         </div>
       ) : (
         <>
-          {/* Completion or holding state (only when there is no next question) */}
+          {/* ── Post-update acknowledgement ─────────────── */}
+          {updateStatus === "success" && graph && (
+            <UpdateAcknowledgement answer={answer} updateResult={result} />
+          )}
+
+          {/* Completion state (only when there is no next question and nothing remains) */}
           {status === "success" && !canAnswer && graph && genuineCompletion && (
             <InvestigationCompleteMessage noQuestionReason={noQuestionReason} />
           )}
-          {status === "success" && !canAnswer && graph && unresolvedRemaining && (
+          {status === "success" && !canAnswer && graph && unresolvedRemaining && updateStatus !== "success" && (
             <div className="rounded-lg border border-gray-200 bg-gray-50 px-5 py-4 text-center">
               <p className="text-sm text-gray-600">There is no further question the engine can justify at the moment.</p>
               <p className="mt-1 text-xs text-gray-500">More evidence may be needed before a next step is clear.</p>