chore(init): 初始化解忧商行项目并完成 Phase 0 基座

backend/internal/modules/chat/adapter.go

@@ -0,0 +1,38 @@
+package chat
+
+import (
+	"gorm.io/gorm"
+	"hfb_sys/backend/internal/model"
+)
+
+// ListingChatCreatorAdapter 适配器,实现 listing.ListingChatCreator 接口
+type ListingChatCreatorAdapter struct {
+	// 无需字段,直接调用包级函数
+}
+
+func NewListingChatCreatorAdapter() *ListingChatCreatorAdapter {
+	return &ListingChatCreatorAdapter{}
+}
+
+// EnsureListingConversation 实现接口
+func (a *ListingChatCreatorAdapter) EnsureListingConversation(tx *gorm.DB, listing model.RentalListing, supportAdminID uint64) (uint64, error) {
+	conv, err := EnsureListingConversation(tx, listing, supportAdminID)
+	if err != nil {
+		return 0, err
+	}
+	return conv.ID, nil
+}
+
+// OrderChatArchiverAdapter 适配器，实现 order.OrderChatArchiver 接口，
+// 供订单封存时在同一事务内解散关联的发布群。
+type OrderChatArchiverAdapter struct{}
+
+func NewOrderChatArchiverAdapter() *OrderChatArchiverAdapter {
+	return &OrderChatArchiverAdapter{}
+}
+
+// ArchiveListingConversation 将商品关联的发布群标记为已归档（解散），
+// 写入一条系统消息提示群聊已被客服解散。会话不存在时静默跳过。
+func (a *OrderChatArchiverAdapter) ArchiveListingConversation(tx *gorm.DB, listingID uint64, reason string) error {
+	return ArchiveListingConversation(tx, listingID, reason)
+}