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/Support.tsx

@@ -12,43 +12,12 @@ import type { TicketDetail } from '../types';
 import { Card } from '@/components/data-display/Card';
 import { Button } from '@/components/primitives/Button';
 import { staggerContainer, staggerItem } from '@/components/motion/transitions';
+import { CloseIcon, ImageIcon, PlusIcon, SendIcon } from '@/components/icons';
 import { usePlatform } from '@/platform';
 import { linkifyText } from '../utils/linkify';
 
 const log = logger.createLogger('Support');
 
-const PlusIcon = () => (
-  <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-    <path strokeLinecap="round" strokeLinejoin="round" d="M12 4.5v15m7.5-7.5h-15" />
-  </svg>
-);
-
-const SendIcon = () => (
-  <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-    <path
-      strokeLinecap="round"
-      strokeLinejoin="round"
-      d="M6 12L3.269 3.126A59.768 59.768 0 0121.485 12 59.77 59.77 0 013.27 20.876L5.999 12zm0 0h7.5"
-    />
-  </svg>
-);
-
-const ImageIcon = () => (
-  <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-    <path
-      strokeLinecap="round"
-      strokeLinejoin="round"
-      d="M2.25 15.75l5.159-5.159a2.25 2.25 0 013.182 0l5.159 5.159m-1.5-1.5l1.409-1.409a2.25 2.25 0 013.182 0l2.909 2.909m-18 3.75h16.5a1.5 1.5 0 001.5-1.5V6a1.5 1.5 0 00-1.5-1.5H3.75A1.5 1.5 0 002.25 6v12a1.5 1.5 0 001.5 1.5zm10.5-11.25h.008v.008h-.008V8.25zm.375 0a.375.375 0 11-.75 0 .375.375 0 01.75 0z"
-    />
-  </svg>
-);
-
-const CloseIcon = () => (
-  <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
-    <path strokeLinecap="round" strokeLinejoin="round" d="M6 18L18 6M6 6l12 12" />
-  </svg>
-);
-
 // Media attachment state
 interface MediaAttachment {
   id: string;
@@ -360,7 +329,7 @@ export default function Support() {
               onClick={() => onRemove(idx)}
               className="absolute -right-1 -top-1 flex h-5 w-5 items-center justify-center rounded-full bg-dark-600 text-dark-300 hover:bg-error-500 hover:text-white"
             >
-              <CloseIcon />
+              <CloseIcon className="h-4 w-4" />
             </button>
           </div>
         ))}
@@ -593,7 +562,7 @@ export default function Support() {
                     disabled={createAttachments.some((a) => a.uploading)}
                     loading={createMutation.isPending}
                   >
-                    <SendIcon />
+                    <SendIcon className="h-4 w-4" />
                     <span className="ml-2">{t('support.send')}</span>
                   </Button>
                   <Button
@@ -745,7 +714,7 @@ export default function Support() {
                         }
                         loading={replyMutation.isPending}
                       >
-                        <SendIcon />
+                        <SendIcon className="h-4 w-4" />
                       </Button>
                     </div>
                     {rateLimitError && (