feat(group-filter): 分组账号过滤控制 — require_oauth_only + require_privacy_set

为 OpenAI/Antigravity/Anthropic/Gemini 分组新增两个布尔控制字段：
- require_oauth_only: 创建/更新账号绑定分组时拒绝 apikey 类型加入
- require_privacy_set: 调度选号时跳过 privacy 未成功设置的账号并标记 error

后端：Ent schema 新增字段 + 迁移、Group CRUD 全链路透传、
      gateway_service 与 openai_account_scheduler 两套调度路径过滤
前端：创建/编辑表单 toggle 开关（OpenAI/Antigravity/Anthropic/Gemini 平台可见）

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

backend/internal/service/openai_account_scheduler.go

@@ -4,6 +4,7 @@ import (
 	"container/heap"
 	"context"
 	"errors"
+	"fmt"
 	"hash/fnv"
 	"math"
 	"sort"
@@ -575,6 +576,12 @@ func (s *defaultOpenAIAccountScheduler) selectByLoadBalance(
 		return nil, 0, 0, 0, errors.New("no available OpenAI accounts")
 	}
 
+	// require_privacy_set: 获取分组信息
+	var schedGroup *Group
+	if req.GroupID != nil && s.service.schedulerSnapshot != nil {
+		schedGroup, _ = s.service.schedulerSnapshot.GetGroupByID(ctx, *req.GroupID)
+	}
+
 	filtered := make([]*Account, 0, len(accounts))
 	loadReq := make([]AccountWithConcurrency, 0, len(accounts))
 	for i := range accounts {
@@ -587,6 +594,12 @@ func (s *defaultOpenAIAccountScheduler) selectByLoadBalance(
 		if !account.IsSchedulable() || !account.IsOpenAI() {
 			continue
 		}
+		// require_privacy_set: 跳过 privacy 未设置的账号并标记异常
+		if schedGroup != nil && schedGroup.RequirePrivacySet && !account.IsPrivacySet() {
+			_ = s.service.accountRepo.SetError(ctx, account.ID,
+				fmt.Sprintf("Privacy not set, required by group [%s]", schedGroup.Name))
+			continue
+		}
 		if req.RequestedModel != "" && !account.IsModelSupported(req.RequestedModel) {
 			continue
 		}