feat: 全局模型新增活跃 Provider 数量统计

- 后端优化查询，使用条件聚合同时获取总 Provider 数和活跃数
- 前端展示格式改为「活跃数/总数」，便于了解可用 Provider 情况

frontend/src/api/endpoints/types.ts

@@ -810,6 +810,7 @@ export interface GlobalModelResponse {
   config?: Record<string, any> | null
   // 统计数据
   provider_count?: number
+  active_provider_count?: number
   usage_count?: number
   created_at: string
   updated_at?: string

frontend/src/features/models/components/ModelDetailDrawer.vue

@@ -386,7 +386,7 @@
                       <Building2 class="w-4 h-4 text-muted-foreground" />
                     </div>
                     <p class="text-2xl font-bold mt-1">
-                      {{ model.provider_count || 0 }}
+                      {{ model.active_provider_count || 0 }}<span class="text-sm text-muted-foreground font-normal">/{{ model.provider_count || 0 }}</span>
                     </p>
                   </div>
                   <div class="p-3 rounded-lg border bg-muted/20">

frontend/src/views/admin/ModelManagement.vue

@@ -168,7 +168,7 @@
                 </TableCell>
                 <TableCell class="text-center">
                   <Badge variant="secondary">
-                    {{ model.provider_count || 0 }}
+                    {{ model.active_provider_count || 0 }}/{{ model.provider_count || 0 }}
                   </Badge>
                 </TableCell>
                 <TableCell class="text-center">
@@ -302,7 +302,7 @@
 
             <!-- 第三行：统计信息 -->
             <div class="flex flex-wrap items-center gap-3 text-xs text-muted-foreground">
-              <span>提供商 {{ model.provider_count || 0 }}</span>
+              <span>提供商 {{ model.active_provider_count || 0 }}/{{ model.provider_count || 0 }}</span>
               <span>调用 {{ formatUsageCount(model.usage_count || 0) }}</span>
               <span
                 v-if="getFirstTierPrice(model, 'input') || getFirstTierPrice(model, 'output')"