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/Polls.tsx

@@ -3,32 +3,7 @@ import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { useTranslation } from 'react-i18next';
 import { pollsApi, PollInfo, PollQuestion } from '../api/polls';
 import { useFocusTrap } from '../hooks/useFocusTrap';
-
-const ClipboardIcon = () => (
-  <svg className="h-6 w-6" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
-    <path
-      strokeLinecap="round"
-      strokeLinejoin="round"
-      d="M9 12h3.75M9 15h3.75M9 18h3.75m3 .75H18a2.25 2.25 0 002.25-2.25V6.108c0-1.135-.845-2.098-1.976-2.192a48.424 48.424 0 00-1.123-.08m-5.801 0c-.065.21-.1.433-.1.664 0 .414.336.75.75.75h4.5a.75.75 0 00.75-.75 2.25 2.25 0 00-.1-.664m-5.8 0A2.251 2.251 0 0113.5 2.25H15c1.012 0 1.867.668 2.15 1.586m-5.8 0c-.376.023-.75.05-1.124.08C9.095 4.01 8.25 4.973 8.25 6.108V8.25m0 0H4.875c-.621 0-1.125.504-1.125 1.125v11.25c0 .621.504 1.125 1.125 1.125h9.75c.621 0 1.125-.504 1.125-1.125V9.375c0-.621-.504-1.125-1.125-1.125H8.25zM6.75 12h.008v.008H6.75V12zm0 3h.008v.008H6.75V15zm0 3h.008v.008H6.75V18z"
-    />
-  </svg>
-);
-
-const GiftIcon = () => (
-  <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
-    <path
-      strokeLinecap="round"
-      strokeLinejoin="round"
-      d="M21 11.25v8.25a1.5 1.5 0 01-1.5 1.5H5.25a1.5 1.5 0 01-1.5-1.5v-8.25M12 4.875A2.625 2.625 0 109.375 7.5H12m0-2.625V7.5m0-2.625A2.625 2.625 0 1114.625 7.5H12m0 0V21m-8.625-9.75h18c.621 0 1.125-.504 1.125-1.125v-1.5c0-.621-.504-1.125-1.125-1.125h-18c-.621 0-1.125.504-1.125 1.125v1.5c0 .621.504 1.125 1.125 1.125z"
-    />
-  </svg>
-);
-
-const CheckIcon = () => (
-  <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-    <path strokeLinecap="round" strokeLinejoin="round" d="M4.5 12.75l6 6 9-13.5" />
-  </svg>
-);
+import { ClipboardIcon, GiftIcon, CheckIcon } from '@/components/icons';
 
 export default function Polls() {
   const { t } = useTranslation();
@@ -131,7 +106,7 @@ export default function Polls() {
   return (
     <div className="space-y-6">
       <div className="flex items-center gap-3">
-        <ClipboardIcon />
+        <ClipboardIcon className="h-6 w-6" />
         <h1 className="text-2xl font-bold text-dark-50 sm:text-3xl">{t('polls.title')}</h1>
       </div>
 
@@ -180,7 +155,7 @@ export default function Polls() {
             {completionMessage && (
               <div className="space-y-4">
                 <div className="rounded-lg bg-success-500/20 p-4 text-center text-success-400">
-                  <CheckIcon />
+                  <CheckIcon className="h-5 w-5" />
                   <p className="mt-2 font-medium">{completionMessage.message}</p>
                   {completionMessage.reward && (
                     <p className="mt-1 text-sm">
@@ -252,7 +227,7 @@ export default function Polls() {
                 </div>
                 {poll.reward_amount && (
                   <div className="flex items-center gap-1 text-accent-400">
-                    <GiftIcon />
+                    <GiftIcon className="h-5 w-5" />
                     <span className="text-sm font-medium">+{poll.reward_amount}</span>
                   </div>
                 )}
@@ -261,7 +236,7 @@ export default function Polls() {
               <div className="mt-4">
                 {poll.is_completed ? (
                   <button disabled className="btn-secondary w-full cursor-not-allowed opacity-50">
-                    <CheckIcon />
+                    <CheckIcon className="h-5 w-5" />
                     <span className="ml-2">{t('polls.completed')}</span>
                   </button>
                 ) : (
@@ -275,7 +250,7 @@ export default function Polls() {
         </div>
       ) : (
         <div className="card py-12 text-center">
-          <ClipboardIcon />
+          <ClipboardIcon className="h-6 w-6" />
           <p className="mt-4 text-dark-400">{t('polls.noPolls')}</p>
         </div>
       )}