Switch the UI icons from mynaui to TDesign

Swap @ng-icons/mynaui for @ng-icons/tdesign-icons (34.0.0, the release
matching @ng-icons/core), drawn at TDesign's native stroke. Each former
mynaui name maps to one TDesign name everywhere it was used; the unused
ArrowLeftRight is dropped. The options button's ellipsis goes from 1.5rem
to 0.8rem: TDesign's dots span 18 of 24 units against mynaui's 8, so this
keeps today's footprint.

Co-Authored-By: Claude <noreply@anthropic.com>

ui/src/app/skins/shadlike/app.html

@@ -2,7 +2,7 @@
   @if (!rpc.available) {
     <div class="flex flex-1 items-center justify-center">
       <div class="max-w-sm rounded-lg border border-border bg-card p-6 text-center shadow-sm">
-        <ng-icon name="mynaXCircle" size="1.5rem" class="text-destructive" />
+        <ng-icon name="tdesignCloseCircle" size="1.5rem" class="text-destructive" />
         <p class="mt-2 text-sm font-medium">{{ i18n.t('app.notConnectedTitle') }}</p>
         <p class="mt-1 text-xs text-muted-foreground">
           {{ i18n.t('app.notConnectedBody') }}
@@ -28,7 +28,7 @@
       (mousedown)="focusManager()"
     >
       <div class="rounded-lg border border-border bg-card px-5 py-4 text-center shadow-xl">
-        <ng-icon name="mynaServers" size="1.25rem" class="text-muted-foreground" />
+        <ng-icon name="tdesignServer" size="1.25rem" class="text-muted-foreground" />
         <p class="mt-1.5 text-xs text-muted-foreground">{{ i18n.t('app.managerOpen') }}</p>
         <button
           class="mt-3 rounded-md bg-primary px-3 py-1.5 text-xs font-medium text-primary-foreground hover:bg-primary/90"