🚧 Refactor backup service

internal/models/schema/mixin/uuid.go

@@ -0,0 +1,36 @@
+package mixin
+
+import (
+	"entgo.io/ent"
+	"entgo.io/ent/schema/field"
+	"entgo.io/ent/schema/index"
+	"entgo.io/ent/schema/mixin"
+	"github.com/google/uuid"
+)
+
+// UUIDMixin 添加 UUID 字段用于跨设备同步
+// 使用 UUIDv7，具有时间有序性，索引性能更好
+type UUIDMixin struct {
+	mixin.Schema
+}
+
+// Fields of the UUIDMixin.
+func (UUIDMixin) Fields() []ent.Field {
+	return []ent.Field{
+		field.String("uuid").
+			DefaultFunc(func() string {
+				return uuid.Must(uuid.NewV7()).String()
+			}).
+			Unique().
+			Immutable().
+			StructTag(`json:"uuid"`).
+			Comment("UUID for cross-device sync (UUIDv7)"),
+	}
+}
+
+// Indexes of the UUIDMixin.
+func (UUIDMixin) Indexes() []ent.Index {
+	return []ent.Index{
+		index.Fields("uuid"),
+	}
+}