fix(prompt-input): 提供可选上下文入口并避免历史路由切换期异常

frontend-web/src/components/ai-elements/prompt-input.tsx

@@ -56,12 +56,11 @@ import {
   type ChangeEventHandler,
   Children,
   type ClipboardEventHandler,
-  type ComponentProps,
-  createContext,
-  type FormEvent,
-  type FormEventHandler,
-  Fragment,
-  type HTMLAttributes,
+  type ComponentProps,
+  createContext,
+  type FormEvent,
+  type FormEventHandler,
+  type HTMLAttributes,
   type KeyboardEventHandler,
   type PropsWithChildren,
   type ReactNode,
@@ -124,9 +123,11 @@ export const usePromptInputController = () => {
   return ctx;
 };
 
-// Optional variants (do NOT throw). Useful for dual-mode components.
-const useOptionalPromptInputController = () =>
-  useContext(PromptInputController);
+// Optional variants (do NOT throw). Useful for dual-mode components and for
+// Fast Refresh transitions where a page can briefly retain the previous
+// provider context instance.
+export const useOptionalPromptInputController = () =>
+  useContext(PromptInputController);
 
 export const useProviderAttachments = () => {
   const ctx = useContext(ProviderAttachmentsContext);
@@ -403,14 +404,14 @@ export function PromptInputAttachments({
   return (
     <div
       className={cn("flex w-full flex-wrap items-center gap-2 p-3", className)}
-      {...props}
-    >
-      {attachments.files.map((file) => (
-        <Fragment key={file.id}>
-          <div className="max-w-60">{children(file)}</div>
-        </Fragment>
-      ))}
-    </div>
+      {...props}
+    >
+      {attachments.files.map((file) => (
+        <div key={file.id} className="max-w-60">
+          {children(file)}
+        </div>
+      ))}
+    </div>
   );
 }