避免生图占位时丢失用户消息

hooks/use-auto-resume.ts

@@ -36,6 +36,9 @@ export function useAutoResume({
   }, [autoResume, initialMessages.at, resumeStream]);
 
   useEffect(() => {
+    if (!autoResume) {
+      return;
+    }
     if (!dataStream) {
       return;
     }
@@ -43,11 +46,16 @@ export function useAutoResume({
       return;
     }
 
-    const dataPart = dataStream[0];
+    const dataPart = dataStream[dataStream.length - 1];
 
     if (dataPart.type === "data-appendMessage") {
       const message = JSON.parse(dataPart.data);
-      setMessages([...initialMessages, message]);
+      setMessages((prev) => {
+        if (prev.some((m) => m.id === message.id)) {
+          return prev;
+        }
+        return [...prev, message];
+      });
     }
-  }, [dataStream, initialMessages, setMessages]);
+  }, [autoResume, dataStream, setMessages]);
 }