feat(sender): optimize input count style (#47)

before
<img width="1118" height="182" alt="图片"
src="https://github.com/user-attachments/assets/91ac4ee2-190d-4975-a85b-cd2c943346dc"
/>
after
<img width="1121" height="185" alt="图片"
src="https://github.com/user-attachments/assets/c302bfed-e93b-4770-916b-e297257e6519"
/>

Author: xx-yoke

.changes/add-inputcount-component.md

@@ -0,0 +1,8 @@
+---
+"@matechat/react": patch:feat
+---
+
+Add `InputCount` component.
+
+-Remove the input count div container and wrap it into a new component, allowing users to customize the input limit.
+-Remove the justify-center style from the div container and add ml-auto to the SenderButton to ensure button remains on the right side.

src/sender.tsx

@@ -20,7 +20,7 @@ export function InputCount({
   ...props
 }: InputCountProps) {
   return (
-    <span className={className} {...props}>
+    <span className={clsx("text-gray-400", className)} {...props}>
       {count} / {limit}
     </span>
   );