feat: support TON and USDT Jetton payments

- add TON chain, token, RPC, address normalization, and order matching support
- add liteclient scanner with masterchain/shard catch-up and Jetton validation
- add TON manual payment verification and focused tests

src/model/service/ton_lite_client.go

@@ -0,0 +1,37 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/xssnick/tonutils-go/liteclient"
+	"github.com/xssnick/tonutils-go/ton"
+)
+
+// ConnectTonLiteAPI builds a tonutils-go API client from a liteserver global
+// config URL. Scanner and manual verification use this same connection setup.
+func ConnectTonLiteAPI(ctx context.Context, configURL string, requestTimeout time.Duration, reconnectLimit int) (ton.APIClientWrapped, func(), error) {
+	configURL = strings.TrimSpace(configURL)
+	if configURL == "" {
+		return nil, func() {}, fmt.Errorf("ton lite config url is empty")
+	}
+	if reconnectLimit <= 0 {
+		reconnectLimit = 3
+	}
+	cfg, err := liteclient.GetConfigFromUrl(ctx, configURL)
+	if err != nil {
+		return nil, func() {}, err
+	}
+	pool := liteclient.NewConnectionPool()
+	pool.SetOnDisconnect(pool.DefaultReconnect(3*time.Second, reconnectLimit))
+	if err = pool.AddConnectionsFromConfig(ctx, cfg); err != nil {
+		pool.Stop()
+		return nil, func() {}, err
+	}
+	base := ton.NewAPIClient(pool, ton.ProofCheckPolicyFast)
+	base.SetTrustedBlockFromConfig(cfg)
+	api := base.WithRetry(2).WithTimeout(requestTimeout).WithLSInfoInErrors()
+	return api, pool.Stop, nil
+}