fix: center ComfyUI logo in sidebar menu button with chevron (#9722)

## Summary

Center the ComfyUI logo in the sidebar menu button after chevron icon
was added, and add padding to floating sidebar item groups.

## Changes

Before / after:
<img width="127" height="417" alt="image"
src="https://github.com/user-attachments/assets/aa327fd9-5550-49aa-b28d-a90435e9d1bc"
/>


- **What**: Use negative margin on chevron icon so it doesn't affect
logo centering. Add `p-0.5` padding to floating sidebar item groups.

## Review Focus

Visual alignment of the logo in both floating and connected sidebar
modes.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9722-fix-center-ComfyUI-logo-in-sidebar-menu-button-with-chevron-31f6d73d3650811a9392cda3070310f9)
by [Unito](https://www.unito.io)

---------

Co-authored-by: github-actions <github-actions@github.com>
Co-authored-by: Alexander Brown <drjkl@comfy.org>
Co-authored-by: GitHub Action <action@github.com>

src/renderer/extensions/vueNodes/widgets/components/layout/WidgetLayoutField.vue

@@ -33,7 +33,7 @@ const hideLayoutField = useHideLayoutField()
       <div
         :class="
           cn(
-            'cursor-default min-w-0 rounded-lg has-[:focus-visible]:ring has-[:focus-visible]:ring-component-node-widget-background-highlighted transition-all',
+            'min-w-0 cursor-default rounded-lg transition-all has-focus-visible:ring has-focus-visible:ring-component-node-widget-background-highlighted',
             widget.borderStyle
           )
         "