Use localized labels for Vue node slots and inputs/outputs (fallback to names) (#5773)

## Summary

Fixes https://github.com/Comfy-Org/ComfyUI_frontend/issues/5697 by
adding internationalization support for Vue node widget labels and
output slot names with fallback to original names.

## Changes

- **What**: Added `label` field to widget data structures and
`localized_name` support for output slots
- **Breaking**: None - all changes maintain backward compatibility with
fallback to original names

## Review Focus

Translation key resolution for node definitions and proper fallback
chain for widget labels and slot names.

## Screenshots (if applicable)

Observe that there is parity between Litegraph and Vue nodes w.r.t.
localization of labels/names.

<img width="3455" height="1417" alt="Screenshot from 2025-09-25
13-19-54"
src="https://github.com/user-attachments/assets/93ee8fae-3671-4175-a941-6462f942d0f1"
/>

<img width="3455" height="1417" alt="Screenshot from 2025-09-25
13-19-38"
src="https://github.com/user-attachments/assets/9573eb86-d74a-40ed-a0b5-e30afd3da6eb"
/>

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-5773-Use-localized-labels-for-Vue-node-slots-and-inputs-outputs-fallback-to-names-2796d73d365081e08fb7d38464f4aa90)
by [Unito](https://www.unito.io)

---------

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

src/composables/graph/useGraphNodeManager.ts

@@ -17,6 +17,7 @@ export interface SafeWidgetData {
   name: string
   type: string
   value: WidgetValue
+  label?: string
   options?: Record<string, unknown>
   callback?: ((value: unknown) => void) | undefined
 }
@@ -86,6 +87,7 @@ export function useGraphNodeManager(graph: LGraph): GraphNodeManager {
           name: widget.name,
           type: widget.type,
           value: value,
+          label: widget.label,
           options: widget.options ? { ...widget.options } : undefined,
           callback: widget.callback
         }