feat(backend/models): add pagination and slice

backend/models/objects.go

@@ -57,3 +57,15 @@ type Session struct {
 	ExpiresAt    time.Time `json:"expires_at"`
 	LastActivity time.Time `json:"last_activity"`
 }
+
+type Pagination struct {
+	Total  int `json:"total"`
+	Offset int `json:"offset"`
+	Limit  int `json:"limit"`
+	Count  int `json:"count"`
+}
+
+type Slice[T any] struct {
+	Pagination Pagination `json:"pagination"`
+	Data       []T        `json:"data"`
+}