refactor: standardize market filenames by data dimension

Split market pair logic into spot and futures files and rename price files to plural data-dimension names without changing behavior.

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

internal/data/market/futures_prices.go

@@ -0,0 +1,85 @@
+package market
+
+import (
+	"context"
+	"strconv"
+	"time"
+
+	"github.com/rs/zerolog/log"
+)
+
+func (ms *MarketData) GetFuturePrice(symbol string) (float64, float64, int64, bool) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	premiums, err := ms.futuresClient.NewPremiumIndexService().Symbol(symbol).Do(ctx)
+	if err != nil {
+		log.Error().Err(err).Str("symbol", symbol).Msg("Failed to fetch futures premium index")
+		return 0, 0, 0, false
+	}
+
+	if len(premiums) == 0 {
+		return 0, 0, 0, false
+	}
+
+	p := premiums[0]
+	markPrice, err := strconv.ParseFloat(p.MarkPrice, 64)
+	if err != nil {
+		return 0, 0, 0, false
+	}
+
+	fundingRate, err := strconv.ParseFloat(p.LastFundingRate, 64)
+	if err != nil {
+		fundingRate = 0
+	}
+
+	return markPrice, fundingRate, p.NextFundingTime, true
+}
+
+type PremiumIndex struct {
+	MarkPrice       float64
+	FundingRate     float64
+	NextFundingTime int64
+}
+
+func (ms *MarketData) GetAllPremiumIndex() (map[string]PremiumIndex, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	premiums, err := ms.futuresClient.NewPremiumIndexService().Do(ctx)
+	if err != nil {
+		log.Error().Err(err).Msg("Failed to fetch all futures premium index")
+		return nil, err
+	}
+
+	result := make(map[string]PremiumIndex, len(premiums))
+	for _, p := range premiums {
+		markPrice, err := strconv.ParseFloat(p.MarkPrice, 64)
+		if err != nil {
+			continue
+		}
+		rate, _ := strconv.ParseFloat(p.LastFundingRate, 64)
+		result[p.Symbol] = PremiumIndex{
+			MarkPrice:       markPrice,
+			FundingRate:     rate,
+			NextFundingTime: p.NextFundingTime,
+		}
+	}
+
+	return result, nil
+}
+
+func (ms *MarketData) GetAllFundRate() (map[string]float64, map[string]int64) {
+	all, err := ms.GetAllPremiumIndex()
+	if err != nil {
+		return make(map[string]float64), make(map[string]int64)
+	}
+
+	rates := make(map[string]float64, len(all))
+	times := make(map[string]int64, len(all))
+	for sym, p := range all {
+		rates[sym] = p.FundingRate
+		times[sym] = p.NextFundingTime
+	}
+	return rates, times
+}