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/Contests.tsx

@@ -2,26 +2,7 @@ import { useState } from 'react';
 import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { useTranslation } from 'react-i18next';
 import { contestsApi, ContestInfo, ContestGameData } from '../api/contests';
-
-const GamepadIcon = () => (
-  <svg className="h-6 w-6" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
-    <path
-      strokeLinecap="round"
-      strokeLinejoin="round"
-      d="M14.25 6.087c0-.355.186-.676.401-.959.221-.29.349-.634.349-1.003 0-1.036-1.007-1.875-2.25-1.875s-2.25.84-2.25 1.875c0 .369.128.713.349 1.003.215.283.401.604.401.959v0a.64.64 0 01-.657.643 48.39 48.39 0 01-4.163-.3c.186 1.613.293 3.25.315 4.907a.656.656 0 01-.658.663v0c-.355 0-.676-.186-.959-.401a1.647 1.647 0 00-1.003-.349c-1.036 0-1.875 1.007-1.875 2.25s.84 2.25 1.875 2.25c.369 0 .713-.128 1.003-.349.283-.215.604-.401.959-.401v0c.31 0 .555.26.532.57a48.039 48.039 0 01-.642 5.056c1.518.19 3.058.309 4.616.354a.64.64 0 00.657-.643v0c0-.355-.186-.676-.401-.959a1.647 1.647 0 01-.349-1.003c0-1.035 1.008-1.875 2.25-1.875 1.243 0 2.25.84 2.25 1.875 0 .369-.128.713-.349 1.003-.215.283-.4.604-.4.959v0c0 .333.277.599.61.58a48.1 48.1 0 005.427-.63 48.05 48.05 0 00.582-4.717.532.532 0 00-.533-.57v0c-.355 0-.676.186-.959.401-.29.221-.634.349-1.003.349-1.035 0-1.875-1.007-1.875-2.25s.84-2.25 1.875-2.25c.37 0 .713.128 1.003.349.283.215.604.401.959.401v0a.656.656 0 00.659-.663 47.703 47.703 0 00-.31-4.82.78.78 0 01.79-.869"
-    />
-  </svg>
-);
-
-const TrophyIcon = () => (
-  <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
-    <path
-      strokeLinecap="round"
-      strokeLinejoin="round"
-      d="M16.5 18.75h-9m9 0a3 3 0 013 3h-15a3 3 0 013-3m9 0v-3.375c0-.621-.503-1.125-1.125-1.125h-.871M7.5 18.75v-3.375c0-.621.504-1.125 1.125-1.125h.872m5.007 0H9.497m5.007 0a7.454 7.454 0 01-.982-3.172M9.497 14.25a7.454 7.454 0 00.981-3.172M5.25 4.236c-.982.143-1.954.317-2.916.52A6.003 6.003 0 007.73 9.728M5.25 4.236V4.5c0 2.108.966 3.99 2.48 5.228M5.25 4.236V2.721C7.456 2.41 9.71 2.25 12 2.25c2.291 0 4.545.16 6.75.47v1.516M7.73 9.728a6.726 6.726 0 002.748 1.35m8.272-6.842V4.5c0 2.108-.966 3.99-2.48 5.228m2.48-5.492a46.32 46.32 0 012.916.52 6.003 6.003 0 01-5.395 4.972m0 0a6.726 6.726 0 01-2.749 1.35m0 0a6.772 6.772 0 01-3.044 0"
-    />
-  </svg>
-);
+import { GamepadIcon, TrophyIcon } from '@/components/icons';
 
 export default function Contests() {
   const { t } = useTranslation();
@@ -92,7 +73,7 @@ export default function Contests() {
   return (
     <div className="space-y-6">
       <div className="flex items-center gap-3">
-        <GamepadIcon />
+        <GamepadIcon className="h-6 w-6" />
         <h1 className="text-2xl font-bold text-dark-50 sm:text-3xl">{t('contests.title')}</h1>
       </div>
 
@@ -255,7 +236,7 @@ export default function Contests() {
         </div>
       ) : (
         <div className="card py-12 text-center">
-          <GamepadIcon />
+          <GamepadIcon className="h-6 w-6" />
           <p className="mt-4 text-dark-400">{t('contests.noContests')}</p>
         </div>
       )}