Fix concurrent map read/write race condition in MarketData

Add sync.RWMutex to protect future and spot price maps accessed by
WebSocket handlers (writers) and Telegram bot handlers (readers).
Also adds Alpha token support with caching.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

internal/data/market/future_price.go

@@ -7,6 +7,8 @@ import (
 )
 
 func (ms *MarketData) GetFuturePrice(symbol string) (float64, float64, int64, bool) {
+	ms.mu.RLock()
+	defer ms.mu.RUnlock()
 	p, ok := ms.futureMarkPrice[symbol]
 	if !ok {
 		return 0, 0, 0, false
@@ -23,6 +25,8 @@ func (ms *MarketData) StartFutureWsMarkPrice() error {
 }
 
 func (ms *MarketData) futureWsMarkPriceHandler(event futures.WsAllMarkPriceEvent) {
+	ms.mu.Lock()
+	defer ms.mu.Unlock()
 	for _, priceEvent := range event {
 		price, err := strconv.ParseFloat(priceEvent.MarkPrice, 64)
 		if err != nil {
@@ -46,5 +50,15 @@ func (ms *MarketData) futureWsErrHandler(err error) {
 }
 
 func (ms *MarketData) GetAllFundRate() (map[string]float64, map[string]int64) {
-	return ms.futureFundingRate, ms.futureNextFundingTime
+	ms.mu.RLock()
+	defer ms.mu.RUnlock()
+	rates := make(map[string]float64, len(ms.futureFundingRate))
+	for k, v := range ms.futureFundingRate {
+		rates[k] = v
+	}
+	times := make(map[string]int64, len(ms.futureNextFundingTime))
+	for k, v := range ms.futureNextFundingTime {
+		times[k] = v
+	}
+	return rates, times
 }