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/.env.example

@@ -1,14 +1,14 @@
 app_name=epusdt
-app_uri=https://dujiaoka.com
+app_uri=https://epusdt.com
 log_level=info
 http_access_log=false
 sql_debug=false
 http_listen=:8000
 
 static_path=/static
-runtime_root_path=/runtime
+runtime_root_path=./runtime
 
-log_save_path=/logs
+log_save_path=./logs
 log_max_size=32
 log_max_age=7
 max_backups=3
@@ -50,22 +50,10 @@ queue_concurrency=10
 queue_poll_interval_ms=1000
 callback_retry_base_seconds=5
 
-tg_bot_token=
-tg_proxy=
-tg_manage=
-
-api_auth_token=
-
 order_expiration_time=10
 order_notice_max_retry=0
-forced_usdt_rate=
+
 api_rate_url=
-tron_grid_api_key=
-solana_rpc_url=
 
-ethereum_ws_url=wss://ethereum.publicnode.com
-
-
-# epay
-epay_pid=
-epay_key=
+# Set to true to re-run the install wizard on next startup.
+install=false