feat: add multi-network payment support

- Redesign payment UI with a two-step flow (select coin/network → pay)
  - Add wallet address validation in Telegram bot
  - Rename NetworkEthereum constant from "eth" to "ethereum"

src/model/mdb/orders_mdb.go

@@ -15,6 +15,7 @@ const (
 type Orders struct {
 	TradeId            string  `gorm:"column:trade_id;uniqueIndex:orders_trade_id_uindex" json:"trade_id"`
 	OrderId            string  `gorm:"column:order_id;uniqueIndex:orders_order_id_uindex" json:"order_id"` // the order id is generated by client, and will notify client when order is paid
+	ParentTradeId      string  `gorm:"column:parent_trade_id;index:idx_orders_parent_trade_id;default:''" json:"parent_trade_id"`
 	BlockTransactionId string  `gorm:"index:orders_block_transaction_id_index;column:block_transaction_id" json:"block_transaction_id"`
 	Amount             float64 `gorm:"column:amount" json:"amount"`
 	Currency           string  `gorm:"column:currency" json:"currency"`
@@ -28,6 +29,7 @@ type Orders struct {
 	Name               string  `gorm:"column:name" json:"name"`
 	CallbackNum        int     `gorm:"column:callback_num;default:0" json:"callback_num"`
 	CallBackConfirm    int     `gorm:"column:callback_confirm;default:2" json:"callback_confirm"`
+	IsSelected         bool    `gorm:"column:is_selected;default:false" json:"is_selected"`
 	PaymentType        string  `gorm:"column:payment_type" json:"payment_type"`
 	BaseModel
 }

src/model/mdb/wallet_address_mdb.go

@@ -8,7 +8,7 @@ const (
 const (
 	NetworkTron     = "tron"
 	NetworkSolana   = "solana"
-	NetworkEthereum = "eth"
+	NetworkEthereum = "ethereum"
 )
 
 type WalletAddress struct {