Feat: Modify the background color of the agent canvas #3221 (#9020)

### What problem does this PR solve?

Feat: Modify the background color of the agent canvas #3221
### Type of change


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

web/src/pages/agent/canvas/node/node-wrapper.tsx

@@ -7,7 +7,7 @@ export function NodeWrapper({ children, className, selected }: IProps) {
   return (
     <section
       className={cn(
-        'bg-background-header-bar p-2.5 rounded-md w-[200px] text-xs',
+        'bg-text-title-invert p-2.5 rounded-md w-[200px] text-xs',
         { 'border border-background-checked': selected },
         className,
       )}