feat: migrate to CoinAnk API and improve chart UI

- Chart improvements: professional styling, popular symbols quick selection, simplified B/S legend
- Data source migration: use CoinAnk API exclusively for all kline data
- Code cleanup: remove Binance WebSocket cache and related code (websocket_client.go, combined_streams.go, monitor.go)
- Log optimization: reduce hook spam, suppress 404 errors, increase P&L diff threshold
- Lighter integration: add order sync functionality, fix market order precision
- Remove ticker merge logic for simplicity

manager/trader_manager.go

@@ -450,7 +450,7 @@ func (tm *TraderManager) LoadUserTradersFromStore(st *store.Store, userID string
 	for _, traderCfg := range traders {
 		// Check if this trader is already loaded
 		if _, exists := tm.traders[traderCfg.ID]; exists {
-			logger.Infof("⚠️ Trader %s already loaded, skipping", traderCfg.Name)
+			// Trader already loaded - this is normal, no need to log
 			continue
 		}