fix(workbench): stream durable fact turn snapshots (#1971)

internal/cloud/server-workbench-http.ts

@@ -1897,11 +1897,22 @@ async function writeTraceRealtimeSnapshot({ writeEvent, options, actor, traceId,
     sessionId,
     threadId,
     traceId,
-    turn: turnSnapshot(context),
+    turn: realtimeTurnSnapshot(context),
     cursor: { traceSeq: traceSnapshotLastSeq(context.trace) }
   });
 }
 
+function realtimeTurnSnapshot(context) {
+  const facts = context?.facts;
+  const traceId = safeTraceId(context?.traceId);
+  if (traceId && facts && context?.factSession) {
+    const factTurn = factTurnForTrace(facts, traceId);
+    const projected = factTurnSnapshot({ turn: factTurn, session: context.factSession, facts, traceId, turnId: context.turnId });
+    if (projected) return projected;
+  }
+  return turnSnapshot(context);
+}
+
 async function writeTraceRealtimeSnapshotSafe(input) {
   try {
     await writeTraceRealtimeSnapshot(input);
@@ -1930,7 +1941,16 @@ async function visibleTraceContext(options, actor, traceId) {
   if (!resultVisible && !session) return { visible: false };
   const trace = await readModel.traceSnapshot(traceId);
   const projection = createWorkbenchTurnProjection({ turnId: traceId, traceId, result, session, trace });
-  return { visible: true, turnId: projection.turnId, traceId, status: projection.status, projection, result, session, trace };
+  const factSessionIdValue = safeSessionId(session?.id ?? result?.sessionId ?? result?.session?.sessionId) ?? null;
+  let facts = emptyFactSet();
+  if (factSessionIdValue && typeof readModel.queryFacts === "function") {
+    try {
+      const factResult = await readModel.queryFacts({ sessionId: factSessionIdValue, families: WORKBENCH_SESSION_DETAIL_FAMILIES, limit: 100 });
+      facts = factResult?.facts ?? facts;
+    } catch { /* realtime falls back to legacy trace snapshot if durable facts are temporarily unavailable */ }
+  }
+  const factSession = factArray(facts.sessions).find((item) => factSessionId(item) === factSessionIdValue) ?? null;
+  return { visible: true, turnId: projection.turnId, traceId, status: projection.status, projection, result, session, trace, facts, factSession };
 }
 
 function traceSnapshotForRealtime(snapshot) {