refactor(10-12): migrate view-level SVGs to AppIcon

- CloudStorageView: cloud icon
- SettingsView: checkCircle, exclamationCircle, x (x2)
- AccountView: checkMark (TOTP enabled indicator)
- AdminAiView: chevronDown (accordion)
- AdminUsersView: copy, check, refresh
- SettingsAccountTab: checkMark (TOTP enabled)
- TotpEnrollment: checkMark (verified state)
- CloudCredentialModal: x, chevronRight
- DocumentView: warning (cloud delete modal)
- SharedView: document icon

frontend/src/components/cloud/CloudCredentialModal.vue

@@ -16,9 +16,7 @@
           aria-label="Close modal"
           class="text-gray-400 hover:text-gray-600 transition-colors"
         >
-          <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M6 18L18 6M6 6l12 12" />
-          </svg>
+          <AppIcon name="x" class="w-5 h-5" />
         </button>
       </div>
 
@@ -73,13 +71,11 @@
             @click="showAdvanced = !showAdvanced"
             class="text-xs text-indigo-600 hover:text-indigo-800 font-medium transition-colors flex items-center gap-1"
           >
-            <svg
+            <AppIcon
+              name="chevronRight"
               class="w-3 h-3 transition-transform"
               :class="{ 'rotate-90': showAdvanced }"
-              fill="none" stroke="currentColor" viewBox="0 0 24 24"
-            >
-              <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" />
-            </svg>
+            />
             Advanced: custom WebDAV endpoint
           </button>
           <div v-if="showAdvanced" class="mt-2">
@@ -188,6 +184,7 @@
 <script setup>
 import { ref, computed, watch } from 'vue'
 import * as api from '../../api/client.js'
+import AppIcon from '../ui/AppIcon.vue'
 
 const props = defineProps({
   show: {