Subgraph/workflow breadcrumbs menu updates (#7852)

## Summary
For users who don't use subgraphs, the workflow name in the top left can
be unnecessarily obstructive so this updated collapses it to a simple
icon until a subgraph is entered.

## Changes

- Add menu button to WorkflowTab for quick workflow actions
- Add menu and back button to SubgraphBreadcrumb
- Extract shared menu items to useBreadcrumbMenu composable
- Add Comfy.RenameWorkflow command for renaming persisted workflows
- Menu always shows root workflow menu, even when in subgraph

## Screenshots (if applicable)

<img width="399" height="396" alt="image"
src="https://github.com/user-attachments/assets/701ab60e-790f-4d1e-a817-dc42b2d98712"
/>
<img width="569" height="381" alt="image"
src="https://github.com/user-attachments/assets/fcea3ab0-8388-4c72-a649-1428c1defd6a"
/>

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7852-Subgraph-workflow-breadcrumbs-menu-updates-2df6d73d3650815b8490ca0a9a92d540)
by [Unito](https://www.unito.io)

---------

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

browser_tests/tests/menu.spec.ts

@@ -133,8 +133,11 @@ test.describe('Menu', () => {
       // Checkmark should be invisible again (panel is hidden)
       await expect(checkmark).toHaveClass(/invisible/)
 
-      // Click outside to close menu
-      await comfyPage.page.locator('body').click({ position: { x: 10, y: 10 } })
+      // Click in top-right corner to close menu (avoid hamburger menu at top-left)
+      const viewport = comfyPage.page.viewportSize()!
+      await comfyPage.page
+        .locator('body')
+        .click({ position: { x: viewport.width - 10, y: 10 } })
 
       // Verify menu is now closed
       await expect(menu).not.toBeVisible()