feat: add admin panel with multi-chain support and notification system

- Add full admin REST API: auth, API keys, chains, chain tokens, wallets,
  orders, RPC nodes, settings, dashboard stats, notifications
- Add JWT-based admin authentication and API key auth middleware
- Add multi-chain listeners: BSC, ETH, Polygon, Plasma, EVM WebSocket
- Add RPC node health check job with automatic failover
- Add Telegram notification channel for order events
- Add installer for first-run database initialization
- Add new DB models: admin_user, api_key, chain, chain_token,
  rpc_node, settings, notification_channel
- Add order statistics aggregation (daily/monthly/by-chain)
- Serve built admin SPA from embedded www/ assets
- Add comprehensive test coverage for all new features

src/model/response/support_response.go

@@ -1,8 +1,8 @@
 package response
 
 type NetworkTokenSupport struct {
-	Network string   `json:"network"`
-	Tokens  []string `json:"tokens"`
+	Network string   `json:"network" example:"tron"`
+	Tokens  []string `json:"tokens" example:"USDT,USDC"`
 }
 
 type SupportedAssetsResponse struct {