修复(#129): 新注册无历史用户不再误命中沉默促销

evaluateInactiveUserPromo 在 ErrRecordNotFound 时之前 return true，导致
新注册无任何订阅历史的用户被错误判定为"沉默用户"命中 inactive_user 规则。
改为 return false 保持判定语义一致：没有历史订阅 ≠ 沉默用户。

Squash from origin/fix/129-新注册误命中沉默促销 (77377ed)

Co-authored-by: multica-agent <github@multica.ai>

internal/logic/common/promoEligibility.go

@@ -175,7 +175,7 @@ func evaluateInactiveUserPromo(
 		Take(&lastSub).Error
 	if err != nil {
 		if errors.Is(err, gorm.ErrRecordNotFound) {
-			return true, ruleExpiresAt, nil
+			return false, time.Time{}, nil
 		}
 		return false, time.Time{}, errors.Wrapf(xerr.NewErrCode(xerr.DatabaseQueryError), "query promo inactive user subscription failed")
 	}

internal/logic/common/promoEligibility_test.go

@@ -2,9 +2,13 @@ package common
 
 import (
 	"context"
+	"regexp"
 	"testing"
 	"time"
 
+	"github.com/DATA-DOG/go-sqlmock"
+	"gorm.io/driver/mysql"
+
 	"github.com/perfect-panel/server/internal/model/promo"
 	"github.com/perfect-panel/server/internal/svc"
 	"gorm.io/gorm"
@@ -134,6 +138,42 @@ func TestEvaluatePromoNewUserRequiresFirstPurchase(t *testing.T) {
 	}
 }
 
+func TestEvaluatePromoRejectsInactiveRuleWhenUserHasNoSubscription(t *testing.T) {
+	db, mock, cleanup := newCommonPromoTestDB(t)
+	defer cleanup()
+
+	model := &fakePromoModel{rules: []*promo.RuleWithPrice{
+		{
+			Rule: promo.Rule{
+				Id:      9,
+				Name:    "inactive",
+				Type:    promo.RuleTypeInactiveUser,
+				Params:  `{"inactive_months":3}`,
+				Enabled: true,
+			},
+			PromoPrice: 100,
+		},
+	}}
+
+	mock.ExpectQuery(regexp.QuoteMeta("SELECT * FROM `user_subscribe` WHERE user_id = ? ORDER BY CASE WHEN expire_time = ? THEN 0 ELSE 1 END, expire_time DESC LIMIT ?")).
+		WithArgs(int64(51640), time.UnixMilli(0), 1).
+		WillReturnError(gorm.ErrRecordNotFound)
+
+	got, err := EvaluatePromo(context.Background(), &svc.ServiceContext{DB: db, PromoModel: model}, 51640, 1, 30, true)
+	if err != nil {
+		t.Fatalf("EvaluatePromo returned error: %v", err)
+	}
+	if got.Eligible {
+		t.Fatal("new user without subscription history should not be eligible for inactive promo")
+	}
+	if got.RuleID != 0 || got.PromoPrice != 0 {
+		t.Fatalf("promo fields = (%d, %d), want zero values", got.RuleID, got.PromoPrice)
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Fatalf("unmet db expectations: %v", err)
+	}
+}
+
 type fakePromoModel struct {
 	rules           []*promo.RuleWithPrice
 	lastSubscribeID int64
@@ -193,3 +233,22 @@ func (m *fakePromoModel) QueryUsageList(context.Context, promo.UsageFilter) (int
 func (m *fakePromoModel) Transaction(context.Context, func(*gorm.DB) error) error {
 	return nil
 }
+
+func newCommonPromoTestDB(t *testing.T) (*gorm.DB, sqlmock.Sqlmock, func()) {
+	t.Helper()
+
+	sqlDB, mock, err := sqlmock.New()
+	if err != nil {
+		t.Fatalf("create sqlmock: %v", err)
+	}
+
+	db, err := gorm.Open(mysql.New(mysql.Config{Conn: sqlDB, SkipInitializeWithVersion: true}), &gorm.Config{})
+	if err != nil {
+		_ = sqlDB.Close()
+		t.Fatalf("open gorm db: %v", err)
+	}
+
+	return db, mock, func() {
+		_ = sqlDB.Close()
+	}
+}