feat(sprint-5): Phase 6 — Staff management UI (list, invite, permissions, revoke)

- /settings/staff: staff account table with role badges + permission chips
- Invite sheet: email + role template + 8 granular permission checkboxes
- Edit permissions dialog with optimistic update
- Revoke access with AlertDialog confirmation
- React Query hooks wired (useStaffListQuery, mutations)
- Full i18n (de/en), mock fallback, loading skeletons
- Sidebar nav updated: Personal → /settings/staff with UserCog icon
- Added @radix-ui/react-checkbox + Checkbox UI component

cannamanage-frontend/src/data/navigations.ts

@@ -30,9 +30,9 @@ export const navigationsData: NavigationType[] = [
         iconName: "FileText",
       },
       {
-        title: "Einstellungen",
-        href: "/settings",
-        iconName: "Settings",
+        title: "Personal",
+        href: "/settings/staff",
+        iconName: "UserCog",
       },
     ],
   },