Fix: Fixed the issue where the prompt word edit box had no scroll bar #3221 (#9215)

### What problem does this PR solve?
Fix: Fixed the issue where the prompt word edit box had no scroll bar
#3221

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

web/src/pages/agent/form/components/prompt-editor/index.tsx

@@ -103,9 +103,12 @@ function PromptContent({
         </div>
       )}
       <ContentEditable
-        className={cn('relative px-2 py-1 focus-visible:outline-none', {
-          'min-h-40': multiLine,
-        })}
+        className={cn(
+          'relative px-2 py-1 focus-visible:outline-none max-h-[50vh] overflow-auto',
+          {
+            'min-h-40': multiLine,
+          },
+        )}
         onBlur={handleBlur}
         onFocus={handleFocus}
       />