feat(cabinet): migrate all icons to the panel's Phosphor set

Replace the cabinet's hand-written heroicons-style SVG icon components with
the Remnawave panel's own icon family — Phosphor via react-icons/pi (Duotone).
All icons now live in a single central barrel (src/components/icons:
index + extended-icons + editor-icons, 144 icons); every feature file imports
from it instead of redefining inline SVGs (~440 icon defs removed).

- Add react-icons dependency
- Desktop nav (AppShell) now uses the central Phosphor icons, removing a
  stroke-vs-duotone inconsistency the partial migration introduced
- Icons with custom props (SortIcon's direction, expandable chevrons) kept as
  thin Phosphor wrappers; the RemnawaveIcon brand logo and animated SVGs
  (checkmarks, spinners) are intentionally left as-is
- Restore the original per-call-site icon sizes wherever the centralized
  default differed (211 call sites)

src/pages/AdminRoleAssign.tsx

@@ -7,74 +7,15 @@ import { adminUsersApi, type UserListItem } from '@/api/adminUsers';
 import { PermissionGate } from '@/components/auth/PermissionGate';
 import { usePermissionStore } from '@/store/permissions';
 import { usePlatform } from '@/platform/hooks/usePlatform';
-
-// === Icons ===
-
-const BackIcon = () => (
-  <svg
-    className="h-5 w-5 text-dark-400"
-    fill="none"
-    viewBox="0 0 24 24"
-    stroke="currentColor"
-    strokeWidth={2}
-  >
-    <path strokeLinecap="round" strokeLinejoin="round" d="M15.75 19.5L8.25 12l7.5-7.5" />
-  </svg>
-);
-
-const SearchIcon = () => (
-  <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-    <path
-      strokeLinecap="round"
-      strokeLinejoin="round"
-      d="M21 21l-5.197-5.197m0 0A7.5 7.5 0 105.196 5.196a7.5 7.5 0 0010.607 10.607z"
-    />
-  </svg>
-);
-
-const ChevronDownIcon = ({ className }: { className?: string }) => (
-  <svg
-    className={className || 'h-4 w-4'}
-    fill="none"
-    viewBox="0 0 24 24"
-    stroke="currentColor"
-    strokeWidth={2}
-  >
-    <path strokeLinecap="round" strokeLinejoin="round" d="M19.5 8.25l-7.5 7.5-7.5-7.5" />
-  </svg>
-);
-
-const ChevronLeftIcon = () => (
-  <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-    <path strokeLinecap="round" strokeLinejoin="round" d="M15.75 19.5L8.25 12l7.5-7.5" />
-  </svg>
-);
-
-const ChevronRightIcon = () => (
-  <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-    <path strokeLinecap="round" strokeLinejoin="round" d="M8.25 4.5l7.5 7.5-7.5 7.5" />
-  </svg>
-);
-
-const XCircleIcon = () => (
-  <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-    <path
-      strokeLinecap="round"
-      strokeLinejoin="round"
-      d="M9.75 9.75l4.5 4.5m0-4.5l-4.5 4.5M21 12a9 9 0 11-18 0 9 9 0 0118 0z"
-    />
-  </svg>
-);
-
-const UserPlusIcon = () => (
-  <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-    <path
-      strokeLinecap="round"
-      strokeLinejoin="round"
-      d="M19 7.5v3m0 0v3m0-3h3m-3 0h-3m-2.25-4.125a3.375 3.375 0 11-6.75 0 3.375 3.375 0 016.75 0zM4 19.235v-.11a6.375 6.375 0 0112.75 0v.109A12.318 12.318 0 0110.374 21c-2.331 0-4.512-.645-6.374-1.766z"
-    />
-  </svg>
-);
+import {
+  BackIcon,
+  SearchIcon,
+  ChevronDownIcon,
+  ChevronLeftIcon,
+  ChevronRightIcon,
+  XCircleIcon,
+  UserPlusIcon,
+} from '@/components/icons';
 
 // === Constants ===
 
@@ -134,7 +75,7 @@ function UserSearchDropdown({
           className="shrink-0 text-dark-400 transition-colors hover:text-dark-200"
           aria-label={t('admin.roleAssign.clearUser')}
         >
-          <XCircleIcon />
+          <XCircleIcon className="h-4 w-4" />
         </button>
       </div>
     );
@@ -647,7 +588,7 @@ export default function AdminRoleAssign() {
                               role: assignment.role_name,
                             })}
                           >
-                            <XCircleIcon />
+                            <XCircleIcon className="h-4 w-4" />
                           </button>
                         </PermissionGate>
                       )}