update minimap and canvas bg to use menu color tokens (#6589)

Update minimap and graph canvas menu (bottom right) to use menu tokens.
Change canvas BG color on default dark theme.

<img width="3840" height="2029" alt="image"
src="https://github.com/user-attachments/assets/6d168981-df27-40c0-829c-59150b8a6a12"
/>


┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6589-wip-Style-graph-canvas-color-2a26d73d365081cb88c4c4bdb2b6d3a5)
by [Unito](https://www.unito.io)

---------

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

src/components/TopMenuSection.vue

@@ -1,11 +1,11 @@
 <template>
-  <div v-if="!workspaceStore.focusMode" class="ml-2 flex pt-1">
+  <div v-if="!workspaceStore.focusMode" class="ml-1 flex gap-x-0.5 pt-1">
     <div class="min-w-0 flex-1">
       <SubgraphBreadcrumb />
     </div>
 
     <div
-      class="actionbar-container pointer-events-auto mx-1 flex h-12 items-center rounded-lg border border-[var(--interface-stroke)] px-2 shadow-interface"
+      class="actionbar-container pointer-events-auto flex h-12 items-center rounded-lg border border-[var(--interface-stroke)] px-2 shadow-interface"
     >
       <!-- Support for legacy topbar elements attached by custom scripts, hidden if no elements present -->
       <div