fix (ai/ui): add missing createdAt (#2342)

Author: lgrammel

.changeset/shaggy-insects-design.md

@@ -0,0 +1,6 @@
+---
+'@ai-sdk/react': patch
+'@ai-sdk/vue': patch
+---
+
+fix (ai/ui): add missing createdAt

packages/react/src/use-chat.ts

@@ -579,6 +579,7 @@ By default, it's set to 0, which will disable the feature.
         messages: input
           ? messagesRef.current.concat({
               id: generateId(),
+              createdAt: new Date(),
               role: 'user',
               content: input,
               experimental_attachments:

packages/vue/src/use-chat.ts

@@ -282,6 +282,7 @@ export function useChat({
       inputValue
         ? messages.value.concat({
             id: generateId(),
+            createdAt: new Date(),
             content: inputValue,
             role: 'user',
           })