test(usage): cover user and admin reasoning effort page display

Mount the real usage tables and assert users only see the requested
effort, while admins can reveal mapped effort via column settings.

frontend/src/components/admin/usage/UsageTable.vue

@@ -91,7 +91,7 @@
         </template>
 
         <template #cell-reasoning_effort="{ row }">
-          <div v-if="hasReasoningEffortMapping(row)" class="space-y-0.5 text-xs">
+          <div v-if="hasReasoningEffortMapping(row)" data-testid="reasoning-effort-cell" class="space-y-0.5 text-xs">
             <div class="font-medium text-gray-900 dark:text-white">
               {{ formatReasoningEffort(row.reasoning_effort) }}
             </div>
@@ -99,7 +99,7 @@
               <span class="mr-0.5">↳</span>{{ formatReasoningEffort(row.upstream_reasoning_effort) }}
             </div>
           </div>
-          <span v-else class="text-sm text-gray-900 dark:text-white">
+          <span v-else data-testid="reasoning-effort-cell" class="text-sm text-gray-900 dark:text-white">
             {{ formatReasoningEffort(row.reasoning_effort) }}
           </span>
         </template>