feat(admin): 分组管理列表新增用量列与账号数分类

分组管理列表增强：

1. 今日/累计用量列：
   - 新增独立端点 GET /admin/groups/usage-summary
   - 一次查询返回所有分组的今日费用和累计费用（actual_cost）
   - 前端异步加载后合并显示在分组列表中

2. 账号数区分可用/限流/总量：
   - 将账号数列从单一总量改为 badge 内多行展示
   - 可用: active + schedulable 的账号数（绿色）
   - 限流: rate_limit/overload/temp_unschedulable 的账号数（橙色，无限流时隐藏）
   - 总量: 全部关联账号数

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/internal/handler/admin/admin_basic_handlers_test.go

@@ -17,8 +17,8 @@ func setupAdminRouter() (*gin.Engine, *stubAdminService) {
 	adminSvc := newStubAdminService()
 
 	userHandler := NewUserHandler(adminSvc, nil)
-	groupHandler := NewGroupHandler(adminSvc)
-	proxyHandler := NewProxyHandler(adminSvc)
+	groupHandler := NewGroupHandler(adminSvc, nil)
+	proxyHandler := NewProxyHandler(adminSvc, nil, nil)
 	redeemHandler := NewRedeemHandler(adminSvc, nil)
 
 	router.GET("/api/v1/admin/users", userHandler.List)

backend/internal/handler/admin/group_handler.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/Wei-Shaw/sub2api/internal/handler/dto"
 	"github.com/Wei-Shaw/sub2api/internal/pkg/response"
+	"github.com/Wei-Shaw/sub2api/internal/pkg/timezone"
 	"github.com/Wei-Shaw/sub2api/internal/service"
 
 	"github.com/gin-gonic/gin"
@@ -16,7 +17,8 @@ import (
 
 // GroupHandler handles admin group management
 type GroupHandler struct {
-	adminService service.AdminService
+	adminService     service.AdminService
+	dashboardService *service.DashboardService
 }
 
 type optionalLimitField struct {
@@ -69,9 +71,10 @@ func (f optionalLimitField) ToServiceInput() *float64 {
 }
 
 // NewGroupHandler creates a new admin group handler
-func NewGroupHandler(adminService service.AdminService) *GroupHandler {
+func NewGroupHandler(adminService service.AdminService, dashboardService *service.DashboardService) *GroupHandler {
 	return &GroupHandler{
-		adminService: adminService,
+		adminService:     adminService,
+		dashboardService: dashboardService,
 	}
 }
 
@@ -363,6 +366,22 @@ func (h *GroupHandler) GetStats(c *gin.Context) {
 	_ = groupID // TODO: implement actual stats
 }
 
+// GetUsageSummary returns today's and cumulative cost for all groups.
+// GET /api/v1/admin/groups/usage-summary?timezone=Asia/Shanghai
+func (h *GroupHandler) GetUsageSummary(c *gin.Context) {
+	userTZ := c.Query("timezone")
+	now := timezone.NowInUserLocation(userTZ)
+	todayStart := timezone.StartOfDayInUserLocation(now, userTZ)
+
+	results, err := h.dashboardService.GetGroupUsageSummary(c.Request.Context(), todayStart)
+	if err != nil {
+		response.Error(c, 500, "Failed to get group usage summary")
+		return
+	}
+
+	response.Success(c, results)
+}
+
 // GetGroupAPIKeys handles getting API keys in a group
 // GET /api/v1/admin/groups/:id/api-keys
 func (h *GroupHandler) GetGroupAPIKeys(c *gin.Context) {

backend/internal/handler/dto/mappers.go

@@ -141,7 +141,9 @@ func GroupFromServiceAdmin(g *service.Group) *AdminGroup {
 		MCPXMLInject:         g.MCPXMLInject,
 		DefaultMappedModel:   g.DefaultMappedModel,
 		SupportedModelScopes: g.SupportedModelScopes,
-		AccountCount:         g.AccountCount,
+		AccountCount:            g.AccountCount,
+		ActiveAccountCount:      g.ActiveAccountCount,
+		RateLimitedAccountCount: g.RateLimitedAccountCount,
 		SortOrder:            g.SortOrder,
 	}
 	if len(g.AccountGroups) > 0 {

backend/internal/handler/dto/types.go

@@ -124,7 +124,9 @@ type AdminGroup struct {
 	// 支持的模型系列（仅 antigravity 平台使用）
 	SupportedModelScopes []string       `json:"supported_model_scopes"`
 	AccountGroups        []AccountGroup `json:"account_groups,omitempty"`
-	AccountCount         int64          `json:"account_count,omitempty"`
+	AccountCount            int64          `json:"account_count,omitempty"`
+	ActiveAccountCount      int64          `json:"active_account_count,omitempty"`
+	RateLimitedAccountCount int64          `json:"rate_limited_account_count,omitempty"`
 
 	// 分组排序
 	SortOrder int `json:"sort_order"`

backend/internal/handler/gateway_handler_warmup_intercept_unit_test.go

@@ -76,7 +76,7 @@ func (f *fakeGroupRepo) ListActiveByPlatform(context.Context, string) ([]service
 	return nil, nil
 }
 func (f *fakeGroupRepo) ExistsByName(context.Context, string) (bool, error)    { return false, nil }
-func (f *fakeGroupRepo) GetAccountCount(context.Context, int64) (int64, error) { return 0, nil }
+func (f *fakeGroupRepo) GetAccountCount(context.Context, int64) (int64, int64, error) { return 0, 0, nil }
 func (f *fakeGroupRepo) DeleteAccountGroupsByGroupID(context.Context, int64) (int64, error) {
 	return 0, nil
 }

backend/internal/handler/sora_gateway_handler_test.go

@@ -273,8 +273,8 @@ func (r *stubGroupRepo) ListActiveByPlatform(ctx context.Context, platform strin
 func (r *stubGroupRepo) ExistsByName(ctx context.Context, name string) (bool, error) {
 	return false, nil
 }
-func (r *stubGroupRepo) GetAccountCount(ctx context.Context, groupID int64) (int64, error) {
-	return 0, nil
+func (r *stubGroupRepo) GetAccountCount(ctx context.Context, groupID int64) (int64, int64, error) {
+	return 0, 0, nil
 }
 func (r *stubGroupRepo) DeleteAccountGroupsByGroupID(ctx context.Context, groupID int64) (int64, error) {
 	return 0, nil