refactor(backend): 引入端口接口模式

backend/internal/service/ports/setting.go

@@ -0,0 +1,17 @@
+package ports
+
+import (
+	"context"
+
+	"sub2api/internal/model"
+)
+
+type SettingRepository interface {
+	Get(ctx context.Context, key string) (*model.Setting, error)
+	GetValue(ctx context.Context, key string) (string, error)
+	Set(ctx context.Context, key, value string) error
+	GetMultiple(ctx context.Context, keys []string) (map[string]string, error)
+	SetMultiple(ctx context.Context, settings map[string]string) error
+	GetAll(ctx context.Context) (map[string]string, error)
+	Delete(ctx context.Context, key string) error
+}