Feature Request: Declarative Admin Sidebar Navigation (Grouping & Role Guards)

[FullThrottle83]

Hi! We're building a production Astro + EmDash CMS application (20+ collections) with custom role access for external users (e.g., Artist portal role).
Currently, the admin sidebar renders a flat list of all collections. To organize our admin dashboard, we currently have to monkey-patch SidebarNav to group collections into collapsible sections (Pages, Bookings & Artists, News) and simplify the view for specific roles.
It would be awesome to support native declarative sidebar configuration in astro.config.mjs, for example:

emdash({
  admin: {
    nav: [
      {
        group: "Bokning & Artister",
        icon: "user-group",
        items: ["artists", "bookings", "pitches"]
      },
      {
        group: "Webbinnehåll",
        items: ["pages", "news", "testimonials"]
      }
    ]
  }
})

This would eliminate the need for custom frontend patches when building complex agency or multi-role applications on EmDash.