feat: fix Lighter V2 integration and improve error handling

- Fix Lighter API field name mismatches (position/size, avg_entry_price/entry_price, sign/side)
- Fix GetBalance return format to match standard fields (totalWalletBalance, totalUnrealizedProfit)
- Fix GetPositions return format to match standard fields (positionAmt, markPrice, unRealizedProfit)
- Add API Key Index field to frontend with explanation
- Update Lighter referral link
- Disable Lighter testnet (mainnet only)
- Add load error tracking for better error messages
- Remove old Lighter V1 implementation files
- Remove test credentials from test files

manager/trader_manager.go

@@ -44,6 +44,7 @@ type CompetitionCache struct {
 // TraderManager manages multiple trader instances
 type TraderManager struct {
 	traders          map[string]*trader.AutoTrader // key: trader ID
+	loadErrors       map[string]error              // key: trader ID, stores last load error
 	competitionCache *CompetitionCache
 	mu               sync.RWMutex
 }
@@ -51,13 +52,21 @@ type TraderManager struct {
 // NewTraderManager creates a trader manager
 func NewTraderManager() *TraderManager {
 	return &TraderManager{
-		traders: make(map[string]*trader.AutoTrader),
+		traders:    make(map[string]*trader.AutoTrader),
+		loadErrors: make(map[string]error),
 		competitionCache: &CompetitionCache{
 			data: make(map[string]interface{}),
 		},
 	}
 }
 
+// GetLoadError returns the last load error for a trader
+func (tm *TraderManager) GetLoadError(traderID string) error {
+	tm.mu.RLock()
+	defer tm.mu.RUnlock()
+	return tm.loadErrors[traderID]
+}
+
 // GetTrader retrieves a trader by ID
 func (tm *TraderManager) GetTrader(id string) (*trader.AutoTrader, error) {
 	tm.mu.RLock()
@@ -496,6 +505,11 @@ func (tm *TraderManager) LoadUserTradersFromStore(st *store.Store, userID string
 		err = tm.addTraderFromStore(traderCfg, aiModelCfg, exchangeCfg, st)
 		if err != nil {
 			logger.Infof("❌ Failed to load trader %s: %v", traderCfg.Name, err)
+			// Save error for later retrieval
+			tm.loadErrors[traderCfg.ID] = err
+		} else {
+			// Clear any previous error on success
+			delete(tm.loadErrors, traderCfg.ID)
 		}
 	}
 
@@ -676,6 +690,8 @@ func (tm *TraderManager) addTraderFromStore(traderCfg *store.Trader, aiModelCfg
 	case "lighter":
 		traderConfig.LighterPrivateKey = exchangeCfg.LighterPrivateKey
 		traderConfig.LighterWalletAddr = exchangeCfg.LighterWalletAddr
+		traderConfig.LighterAPIKeyPrivateKey = exchangeCfg.LighterAPIKeyPrivateKey
+		traderConfig.LighterAPIKeyIndex = exchangeCfg.LighterAPIKeyIndex
 		traderConfig.LighterTestnet = exchangeCfg.Testnet
 	}