feat: add producer account management

backend/api/internal/models/entity_test.go

@@ -0,0 +1,21 @@
+package models
+
+import (
+	"reflect"
+	"testing"
+
+	"gorm.io/gorm"
+)
+
+func TestEntityDeletedAtEnablesSoftDelete(t *testing.T) {
+	field, ok := reflect.TypeOf(Entity{}).FieldByName("DeletedAt")
+	if !ok {
+		t.Fatal("Entity 缺少 DeletedAt 软删除字段")
+	}
+	if field.Type != reflect.TypeOf(gorm.DeletedAt{}) {
+		t.Fatalf("DeletedAt 类型为 %v，期望 gorm.DeletedAt", field.Type)
+	}
+	if got := field.Tag.Get("gorm"); got != "index" {
+		t.Fatalf("DeletedAt gorm 标签为 %q，期望 %q", got, "index")
+	}
+}