fix: preserve chat order and published page scripts

chat-finish-sync.mjs

@@ -30,8 +30,41 @@ export function mergeConversationSnapshot(current, incoming) {
   }
   const base = Array.isArray(current) ? current : [];
   const incomingIds = new Set(incoming.map((message) => message?.id).filter(Boolean));
-  const localOnly = base.filter((message) => message?.id && !incomingIds.has(message.id));
-  return localOnly.length ? [...incoming, ...localOnly] : incoming;
+  const localOnlyByNextAnchor = new Map();
+
+  // Keep the regression-guard behaviour of retaining local streamed messages,
+  // but put them back between the same server messages instead of appending the
+  // whole local tail. Finish/UpdateConversation snapshots can temporarily omit
+  // a middle message while Goose is still persisting it.
+  for (let index = 0; index < base.length; index += 1) {
+    const message = base[index];
+    if (!message?.id || incomingIds.has(message.id)) continue;
+
+    let nextAnchor = null;
+    for (let cursor = index + 1; cursor < base.length; cursor += 1) {
+      const candidateId = base[cursor]?.id;
+      if (candidateId && incomingIds.has(candidateId)) {
+        nextAnchor = candidateId;
+        break;
+      }
+    }
+
+    const bucket = localOnlyByNextAnchor.get(nextAnchor) ?? [];
+    bucket.push(message);
+    localOnlyByNextAnchor.set(nextAnchor, bucket);
+  }
+
+  if (localOnlyByNextAnchor.size === 0) return incoming;
+
+  const merged = [];
+  for (const message of incoming) {
+    const before = localOnlyByNextAnchor.get(message?.id);
+    if (before?.length) merged.push(...before);
+    merged.push(message);
+  }
+  const trailing = localOnlyByNextAnchor.get(null);
+  if (trailing?.length) merged.push(...trailing);
+  return merged;
 }
 
 /**