Update semantic token usage to match current design system conventions:
- Use bg-component-node-widget-background (main's naming)
- Use text-base-foreground for primary text (main's convention)
- Use text-secondary for icons and secondary text (semantic token)
- Use bg-interface-stroke and bg-button-icon (semantic tokens)
- Use hover:bg-interface-menu-component-surface-hovered
- Use bg-interface-menu-component-surface-selected
This preserves the PR's intent of migrating to semantic tokens while
adopting the evolved token names from main.