fix(accounts): show email and add usage refresh button for OpenAI OAuth

- AccountsView: display email under account name by checking extra.email
  and credentials.email in addition to extra.email_address; OpenAI OAuth
  stores email under the 'email' key while Anthropic uses 'email_address'
- AccountUsageCell: add per-account refresh button to the OpenAI OAuth
  usage section, identical to the existing Anthropic OAuth pattern;
  reuses loadActiveUsage, activeQueryLoading, and the activeQuery i18n key

frontend/src/components/account/AccountUsageCell.vue

@@ -126,6 +126,30 @@
           :show-now-when-idle="true"
           color="emerald"
         />
+        <div class="flex items-center gap-1.5 mt-0.5">
+          <button
+            type="button"
+            class="inline-flex items-center gap-0.5 rounded px-1.5 py-0.5 text-[9px] font-medium text-blue-600 hover:bg-blue-50 dark:text-blue-400 dark:hover:bg-blue-900/30 transition-colors"
+            :disabled="activeQueryLoading"
+            @click="loadActiveUsage"
+          >
+            <svg
+              class="h-2.5 w-2.5"
+              :class="{ 'animate-spin': activeQueryLoading }"
+              fill="none"
+              stroke="currentColor"
+              viewBox="0 0 24 24"
+            >
+              <path
+                stroke-linecap="round"
+                stroke-linejoin="round"
+                stroke-width="2"
+                d="M4 4v5h.582m15.356 2A8.001 8.001 0 004.582 9m0 0H9m11 11v-5h-.581m0 0a8.003 8.003 0 01-15.357-2m15.357 2H15"
+              />
+            </svg>
+            {{ t('admin.accounts.usageWindow.activeQuery') }}
+          </button>
+        </div>
       </div>
       <div v-else-if="loading" class="space-y-1.5">
         <div class="flex items-center gap-1">
@@ -1070,7 +1094,7 @@ const attachVisibilityObserver = () => {
 const loadActiveUsage = async () => {
   activeQueryLoading.value = true
   try {
-    usageInfo.value = await adminAPI.accounts.getUsage(props.account.id, 'active')
+    usageInfo.value = await adminAPI.accounts.getUsage(props.account.id, 'active', true)
   } catch (e: any) {
     console.error('Failed to load active usage:', e)
   } finally {

frontend/src/views/admin/AccountsView.vue

@@ -214,11 +214,11 @@
             <div class="flex flex-col">
               <span class="font-medium text-gray-900 dark:text-white">{{ value }}</span>
               <span
-                v-if="row.extra?.email_address"
+                v-if="row.extra?.email_address || row.extra?.email || row.credentials?.email"
                 class="text-xs text-gray-500 dark:text-gray-400 truncate max-w-[200px]"
-                :title="row.extra.email_address"
+                :title="String(row.extra?.email_address || row.extra?.email || row.credentials?.email)"
               >
-                {{ row.extra.email_address }}
+                {{ row.extra?.email_address || row.extra?.email || row.credentials?.email }}
               </span>
             </div>
           </template>