refactor(10-12): migrate cloud/settings/UI SVGs to AppIcon

- SearchableModelSelect: chevronDown + pencilEdit
- SettingsCloudTab: warning (x2) + cloud icons
- CloudProviderTreeItem: cloud icon
- CloudFolderTreeItem: folder + fileDoc icons

frontend/src/components/ui/SearchableModelSelect.vue

@@ -24,12 +24,10 @@
         class="absolute inset-y-0 right-0 flex items-center px-2 text-gray-400 hover:text-gray-600"
         @mousedown.prevent="toggleOpen"
       >
-        <svg
+        <AppIcon
+          name="chevronDown"
           :class="['w-4 h-4 transition-transform', isOpen ? 'rotate-180' : '']"
-          fill="none" stroke="currentColor" viewBox="0 0 24 24"
-        >
-          <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M19 9l-7 7-7-7" />
-        </svg>
+        />
       </button>
     </div>
 
@@ -82,9 +80,7 @@
           class="sticky bottom-0 flex items-center gap-2 px-3 py-2 text-sm text-indigo-600 font-medium border-t border-gray-100 bg-white cursor-pointer hover:bg-indigo-50 select-none"
           @mousedown.prevent="selectManual"
         >
-          <svg class="w-3.5 h-3.5 shrink-0" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M15.232 5.232l3.536 3.536m-2.036-5.036a2.5 2.5 0 113.536 3.536L6.5 21.036H3v-3.572L16.732 3.732z" />
-          </svg>
+          <AppIcon name="pencilEdit" class="w-3.5 h-3.5 shrink-0" />
           <span>{{ query.trim() ? `Use "${query.trim()}"` : 'Enter model name manually' }}</span>
         </li>
       </ul>
@@ -95,6 +91,7 @@
 <script setup>
 import { ref, computed, watch, nextTick, onUnmounted } from 'vue'
 import { getAiModels } from '../../api/client.js'
+import AppIcon from './AppIcon.vue'
 
 const props = defineProps({
   modelValue: { type: String, default: '' },