테넌트 목록 조회 cursor기반으로 재구성. 사용자 metadata 미사용 필드 제거

backend/internal/pagination/cursor_test.go

@@ -0,0 +1,55 @@
+package pagination
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+type testItem struct {
+	id        string
+	createdAt time.Time
+}
+
+func TestPageByCursorReturnsNextCursorAndNextPage(t *testing.T) {
+	now := time.Date(2026, 5, 13, 8, 0, 0, 0, time.UTC)
+	items := []testItem{
+		{id: "c", createdAt: now},
+		{id: "b", createdAt: now.Add(-time.Minute)},
+		{id: "a", createdAt: now.Add(-2 * time.Minute)},
+	}
+	key := func(item testItem) (time.Time, string) {
+		return item.createdAt, item.id
+	}
+
+	firstPage, nextCursor, err := PageByCursor(items, 2, "", key)
+	require.NoError(t, err)
+	require.Len(t, firstPage, 2)
+	require.NotEmpty(t, nextCursor)
+
+	secondPage, nextCursor, err := PageByCursor(items, 2, nextCursor, key)
+	require.NoError(t, err)
+	require.Len(t, secondPage, 1)
+	require.Empty(t, nextCursor)
+	require.Equal(t, "a", secondPage[0].id)
+}
+
+func TestSortByKeyDescUsesIDAsTieBreaker(t *testing.T) {
+	now := time.Date(2026, 5, 13, 8, 0, 0, 0, time.UTC)
+	items := []testItem{
+		{id: "a", createdAt: now},
+		{id: "c", createdAt: now},
+		{id: "b", createdAt: now},
+	}
+
+	SortByKeyDesc(items, func(item testItem) (time.Time, string) {
+		return item.createdAt, item.id
+	})
+
+	require.Equal(t, []string{"c", "b", "a"}, []string{
+		items[0].id,
+		items[1].id,
+		items[2].id,
+	})
+}