rework minimap, toolbox, and menu designs with unified theming (#6038)

## Summary

This PR redesigns the graph canvas interface components including
minimap, toolbox, and menu systems with updated spacing, colors, and
interaction patterns - using the design tokens directly from Figma,
which can be used elsewhere going forward.

There are some other changes to the designs, outlined
[here](https://www.notion.so/comfy-org/Update-Minimap-Menu-v2-2886d73d365080e88e12f8df027019c0):

- [x]  Update/standardize the padding between viewport and toolbox
- [x] Update toolbox component’s style to match the other floating menus
style (border radius, height, padding and follow theme colors)
- [x]  Expose the minimap button
- [x]  Remove the focus button and delete it’s keybinding
- [x]  Group the hand and the default cursor buttons


https://github.com/user-attachments/assets/92542e60-c32d-4a21-a6f6-e72837a70b17

## Review Focus

New CSS variables for cross-component theming consistency and
CanvasModeSelector component extraction for improved code organization.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6038-rework-minimap-toolbox-and-menu-designs-with-unified-theming-28b6d73d36508191a0c6cf8036d965c4)
by [Unito](https://www.unito.io)

---------

Co-authored-by: github-actions <github-actions@github.com>

src/components/graph/SelectionToolbox.vue

@@ -7,11 +7,10 @@
     <Transition name="slide-up">
       <Panel
         v-if="visible"
-        class="selection-toolbox pointer-events-auto rounded-lg"
-        :style="`backgroundColor: ${containerStyles.backgroundColor};`"
+        class="selection-toolbox pointer-events-auto rounded-lg border border-interface-stroke bg-interface-panel-surface"
         :pt="{
           header: 'hidden',
-          content: 'p-1 h-10 flex flex-row gap-1'
+          content: 'p-2 h-12 flex flex-row gap-1'
         }"
         @wheel="canvasInteractions.forwardEventToCanvas"
       >
@@ -65,7 +64,6 @@ import { useSelectionToolboxPosition } from '@/composables/canvas/useSelectionTo
 import { useSelectionState } from '@/composables/graph/useSelectionState'
 import { useCanvasStore } from '@/renderer/core/canvas/canvasStore'
 import { useCanvasInteractions } from '@/renderer/core/canvas/useCanvasInteractions'
-import { useMinimap } from '@/renderer/extensions/minimap/composables/useMinimap'
 import { useExtensionService } from '@/services/extensionService'
 import { useCommandStore } from '@/stores/commandStore'
 import type { ComfyCommandImpl } from '@/stores/commandStore'
@@ -78,8 +76,6 @@ const commandStore = useCommandStore()
 const canvasStore = useCanvasStore()
 const extensionService = useExtensionService()
 const canvasInteractions = useCanvasInteractions()
-const minimap = useMinimap()
-const containerStyles = minimap.containerStyles
 
 const toolboxRef = ref<HTMLElement | undefined>()
 const { visible } = useSelectionToolboxPosition(toolboxRef)