Feat: Replace color variables according to design draft #3221 (#9305)

### What problem does this PR solve?

Feat: Replace color variables according to design draft #3221

### Type of change


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

web/src/pages/agent/canvas/node/handle.tsx

@@ -28,7 +28,7 @@ export function CommonHandle({
       <Handle
         {...props}
         className={cn(
-          'inline-flex justify-center items-center !bg-background-checked !size-4 !rounded-sm !border-none ',
+          'inline-flex justify-center items-center !bg-accent-primary !size-4 !rounded-sm !border-none ',
           className,
         )}
         onClick={(e) => {