feat: mobile UI overhaul — iPhone-style app grid, icon-only tab bar, fullscreen app sessions

- Add AppIconGrid: 4-column swipeable icon grid with page dots for My Apps on mobile
- Tab bar: remove text labels, square icon-only buttons (w-14 h-14), doubled padding
- Hide tab bar and top context tabs when app session is open
- App session header hidden on mobile, replaced with floating glass close button
- App sessions now render fullscreen on mobile without nav chrome

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

neode-ui/src/views/Apps.vue

@@ -91,8 +91,16 @@
       <p class="text-white/70">{{ t('apps.noResults', { query: searchQuery }) }}</p>
     </div>
 
-    <!-- Apps Grid -->
-    <div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4 pb-6">
+    <!-- Mobile: iPhone-style icon grid -->
+    <div class="md:hidden">
+      <AppIconGrid
+        :apps="filteredPackageEntries as [string, PackageDataEntry][]"
+        @go-to-app="goToApp"
+      />
+    </div>
+
+    <!-- Desktop: Card grid -->
+    <div class="hidden md:grid grid-cols-2 lg:grid-cols-3 gap-4 pb-6">
       <AppCard
         v-for="([id, pkg], index) in filteredPackageEntries"
         :key="id"
@@ -147,6 +155,7 @@ import { useServerStore } from '@/stores/server'
 import { useAppLauncherStore } from '@/stores/appLauncher'
 import type { PackageDataEntry } from '@/types/api'
 import AppCard from './apps/AppCard.vue'
+import AppIconGrid from './apps/AppIconGrid.vue'
 import AppsUninstallModal from './apps/AppsUninstallModal.vue'
 import { useAppsActions } from './apps/useAppsActions'
 import {