fix: harden phase summary open questions

frontend/src/viewers/ArtifactView.test.tsx

@@ -129,6 +129,31 @@ test("phase v2 dispatches to PhaseSummaryViewer", () => {
   expect(screen.getByText("Riassunto della fase.")).toBeInTheDocument();
 });
 
+test("phase v2 tolerates the malformed open question from the latest session", () => {
+  render(
+    <ArtifactView
+      artifact={{
+        kind: "phase",
+        data: {
+          schema_version: 2,
+          phase: { id: "F6", num: 6, name: "Piano CTE" },
+          summary: "Piano completato.",
+          open_questions: [
+            {
+              label: "pazienti_finale restituisce 0 righe",
+              question: "Verificare se la condizione temporale è troppo restrittiva",
+            },
+          ],
+        },
+      }}
+    />,
+  );
+
+  expect(
+    screen.getByText("Verificare se la condizione temporale è troppo restrittiva"),
+  ).toBeInTheDocument();
+});
+
 test("phase v1 (no schema_version) still renders via legacy markdown/structured path", () => {
   render(
     <ArtifactView

frontend/src/viewers/PhaseSummaryViewer.test.tsx

@@ -81,6 +81,22 @@ test("renders open_questions as a bullet list", () => {
   expect(screen.getByText("Serve confermare la finestra temporale?")).toBeInTheDocument();
 });
 
+test("renders a legacy structured open question safely", () => {
+  const malformed = {
+    ...phase,
+    open_questions: [
+      {
+        label: "pazienti_finale restituisce 0 righe",
+        question: "Verificare se i filtri sono troppo restrittivi",
+      },
+    ],
+  } as unknown as PhaseSummaryV2;
+
+  render(<PhaseSummaryViewer phase={malformed} />);
+
+  expect(screen.getByText("Verificare se i filtri sono troppo restrittivi")).toBeInTheDocument();
+});
+
 test("renders a section with title only (no items key) without crashing", () => {
   const proseOnly: PhaseSummaryV2 = {
     schema_version: 2,

frontend/src/viewers/PhaseSummaryViewer.tsx

@@ -1,7 +1,14 @@
 import { Badge } from "../components/ui/badge";
 import { MarkdownView } from "./MarkdownView";
 import { statusBadgeClass } from "./statusBadge";
-import type { PhaseCheck, PhaseSection, PhaseSectionItem, PhaseSummaryV2, PhaseTable } from "./artifactV2";
+import {
+  phaseOpenQuestionText,
+  type PhaseCheck,
+  type PhaseSection,
+  type PhaseSectionItem,
+  type PhaseSummaryV2,
+  type PhaseTable,
+} from "./artifactV2";
 
 const CODE_CHIP = "rounded-md bg-muted px-1.5 py-0.5 font-mono text-xs text-foreground/90";
 
@@ -69,6 +76,12 @@ function TableRecap({ table }: { table: PhaseTable }) {
 }
 
 export function PhaseSummaryViewer({ phase }: { phase: PhaseSummaryV2 }) {
+  const openQuestions = Array.isArray(phase.open_questions)
+    ? (phase.open_questions as unknown[])
+        .map(phaseOpenQuestionText)
+        .filter((question): question is string => question !== null)
+    : [];
+
   return (
     <div className="flex flex-col gap-4">
       <h3 className="thot-label">
@@ -101,11 +114,11 @@ export function PhaseSummaryViewer({ phase }: { phase: PhaseSummaryV2 }) {
         </div>
       )}
 
-      {phase.open_questions && phase.open_questions.length > 0 && (
+      {openQuestions.length > 0 && (
         <div>
           <h4 className="thot-label mb-1">Open questions</h4>
           <ul className="list-disc space-y-1 pl-5 text-sm text-foreground/90 marker:text-muted-foreground">
-            {phase.open_questions.map((q, i) => (
+            {openQuestions.map((q, i) => (
               <li key={i}>{q}</li>
             ))}
           </ul>

frontend/src/viewers/artifactV2.ts

@@ -119,3 +119,18 @@ export interface PhaseSummaryV2 {
   tables?: PhaseTable[];
   open_questions?: string[];
 }
+
+/** Defensive compatibility for malformed v2 artifacts persisted before the gate
+ * enforced `open_questions: string[]`. New payloads stay strictly typed as strings. */
+export function phaseOpenQuestionText(value: unknown): string | null {
+  if (typeof value === "string") return value.trim() || null;
+  if (typeof value === "number" || typeof value === "boolean") return String(value);
+  if (!value || typeof value !== "object" || Array.isArray(value)) return null;
+
+  const record = value as Record<string, unknown>;
+  for (const field of ["question", "label"]) {
+    const text = record[field];
+    if (typeof text === "string" && text.trim()) return text.trim();
+  }
+  return null;
+}