chore(init): 初始化解忧商行项目并完成 Phase 0 基座

backend/internal/modules/listing/handler.go

@@ -0,0 +1,28 @@
+package listing
+
+import (
+	filemodule "hfb_sys/backend/internal/modules/file"
+)
+
+type Handler struct {
+	service                  *Service
+	storage                  *filemodule.Storage
+	externalUploadSecret     string
+	externalUploadAllowedIPs []string
+}
+
+const maxExternalUploadBodyBytes = 256 * 1024
+
+type HandlerOptions struct {
+	ExternalUploadSecret     string
+	ExternalUploadAllowedIPs []string
+}
+
+func NewHandler(service *Service, storage *filemodule.Storage, opts ...HandlerOptions) *Handler {
+	handler := &Handler{service: service, storage: storage}
+	if len(opts) > 0 {
+		handler.externalUploadSecret = opts[0].ExternalUploadSecret
+		handler.externalUploadAllowedIPs = opts[0].ExternalUploadAllowedIPs
+	}
+	return handler
+}