Feature：Add a loading status to the agent canvas page. (#11733)

### What problem does this PR solve?

Feature：Add a loading status to the agent canvas page.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

web/src/pages/agent/form-sheet/next.tsx

@@ -55,7 +55,7 @@ const FormSheet = ({
     <Sheet open={visible} modal={false}>
       <SheetContent
         className={cn('top-20 p-0 flex flex-col pb-20', {
-          'right-[620px]': chatVisible,
+          'right-[clamp(0px,34%,620px)]': chatVisible,
         })}
         closeIcon={false}
       >