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

trader/lighter_trader_v2_orders.go

@@ -5,8 +5,9 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"nofx/logger"
+	"mime/multipart"
 	"net/http"
+	"nofx/logger"
 	"strconv"
 
 	"github.com/elliottech/lighter-go/types"
@@ -271,10 +272,11 @@ func (t *LighterTraderV2) CancelOrder(symbol, orderID string) error {
 	}
 
 	// Get market index
-	marketIndex, err := t.getMarketIndex(symbol)
+	marketIndexU16, err := t.getMarketIndex(symbol)
 	if err != nil {
 		return fmt.Errorf("failed to get market index: %w", err)
 	}
+	marketIndex := uint8(marketIndexU16) // SDK expects uint8
 
 	// Convert orderID to int64
 	orderIndex, err := strconv.ParseInt(orderID, 10, 64)
@@ -313,30 +315,37 @@ func (t *LighterTraderV2) CancelOrder(symbol, orderID string) error {
 	return nil
 }
 
-// submitCancelOrder Submit signed cancel order to LIGHTER API
+// submitCancelOrder Submit signed cancel order to LIGHTER API using multipart/form-data
 func (t *LighterTraderV2) submitCancelOrder(signedTx []byte) (map[string]interface{}, error) {
 	const TX_TYPE_CANCEL_ORDER = 15
 
-	// Build request
-	req := SendTxRequest{
-		TxType:          TX_TYPE_CANCEL_ORDER,
-		TxInfo:          string(signedTx),
-		PriceProtection: false, // Cancel order doesn't need price protection
+	// Build multipart form data (Lighter API requires form-data, not JSON)
+	var body bytes.Buffer
+	writer := multipart.NewWriter(&body)
+
+	// Add tx_type field
+	if err := writer.WriteField("tx_type", strconv.Itoa(TX_TYPE_CANCEL_ORDER)); err != nil {
+		return nil, fmt.Errorf("failed to write tx_type: %w", err)
 	}
 
-	reqBody, err := json.Marshal(req)
-	if err != nil {
-		return nil, fmt.Errorf("failed to serialize request: %w", err)
+	// Add tx_info field
+	if err := writer.WriteField("tx_info", string(signedTx)); err != nil {
+		return nil, fmt.Errorf("failed to write tx_info: %w", err)
+	}
+
+	// Close multipart writer
+	if err := writer.Close(); err != nil {
+		return nil, fmt.Errorf("failed to close multipart writer: %w", err)
 	}
 
 	// Send POST request to /api/v1/sendTx
 	endpoint := fmt.Sprintf("%s/api/v1/sendTx", t.baseURL)
-	httpReq, err := http.NewRequest("POST", endpoint, bytes.NewBuffer(reqBody))
+	httpReq, err := http.NewRequest("POST", endpoint, &body)
 	if err != nil {
 		return nil, err
 	}
 
-	httpReq.Header.Set("Content-Type", "application/json")
+	httpReq.Header.Set("Content-Type", writer.FormDataContentType())
 
 	resp, err := t.client.Do(httpReq)
 	if err != nil {
@@ -344,15 +353,15 @@ func (t *LighterTraderV2) submitCancelOrder(signedTx []byte) (map[string]interfa
 	}
 	defer resp.Body.Close()
 
-	body, err := io.ReadAll(resp.Body)
+	respBody, err := io.ReadAll(resp.Body)
 	if err != nil {
 		return nil, err
 	}
 
 	// Parse response
 	var sendResp SendTxResponse
-	if err := json.Unmarshal(body, &sendResp); err != nil {
-		return nil, fmt.Errorf("failed to parse response: %w, body: %s", err, string(body))
+	if err := json.Unmarshal(respBody, &sendResp); err != nil {
+		return nil, fmt.Errorf("failed to parse response: %w, body: %s", err, string(respBody))
 	}
 
 	// Check response code