style(ui): center plugin browser tabs (#11205)

💄 style(ui): center plugin browser tabs

Center the tab items in the plugin browser component for better visual alignment and improved user experience.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude <noreply@anthropic.com>

src/renderer/src/pages/settings/AgentSettings/components/PluginBrowser.tsx

@@ -263,6 +263,7 @@ export const PluginBrowser: FC<PluginBrowserProps> = ({
           items={pluginTypeTabItems}
           className="w-full"
           size="small"
+          centered
         />
       </div>