feat: unify NofxOS data provider and fix language consistency

- Add unified NofxOS API key configuration in IndicatorEditor
- Add language field to StrategyConfig for consistent prompt generation
- Auto-update prompt sections when interface language changes
- Remove scattered URL inputs from CoinSourceEditor and IndicatorEditor
- Create nofxos provider package with formatted data output
- Update kernel engine to use config-based language setting

provider/nofxos/ai500.go

@@ -0,0 +1,163 @@
+package nofxos
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"strings"
+	"time"
+)
+
+// CoinData represents AI500 coin information
+type CoinData struct {
+	Pair            string  `json:"pair"`             // Trading pair symbol (e.g.: BTCUSDT)
+	Score           float64 `json:"score"`            // Current AI score (0-100)
+	StartTime       int64   `json:"start_time"`       // Start time (Unix timestamp)
+	StartPrice      float64 `json:"start_price"`      // Start price
+	LastScore       float64 `json:"last_score"`       // Latest score
+	MaxScore        float64 `json:"max_score"`        // Highest score
+	MaxPrice        float64 `json:"max_price"`        // Highest price
+	IncreasePercent float64 `json:"increase_percent"` // Increase percentage (already x100)
+	IsAvailable     bool    `json:"-"`                // Whether tradable (internal use)
+}
+
+// AI500Response is the API response structure
+type AI500Response struct {
+	Success bool `json:"success"`
+	Data    struct {
+		Coins []CoinData `json:"coins"`
+		Count int        `json:"count"`
+	} `json:"data"`
+}
+
+// GetAI500List retrieves AI500 coin list with retry mechanism
+func (c *Client) GetAI500List() ([]CoinData, error) {
+	maxRetries := 3
+	var lastErr error
+
+	for attempt := 1; attempt <= maxRetries; attempt++ {
+		if attempt > 1 {
+			log.Printf("⚠️  Retry attempt %d of %d to fetch AI500 data...", attempt, maxRetries)
+			time.Sleep(2 * time.Second)
+		}
+
+		coins, err := c.fetchAI500()
+		if err == nil {
+			if attempt > 1 {
+				log.Printf("✓ Retry attempt %d succeeded", attempt)
+			}
+			return coins, nil
+		}
+
+		lastErr = err
+		log.Printf("❌ AI500 request attempt %d failed: %v", attempt, err)
+	}
+
+	return nil, fmt.Errorf("all AI500 API requests failed: %w", lastErr)
+}
+
+func (c *Client) fetchAI500() ([]CoinData, error) {
+	log.Printf("🔄 Requesting AI500 data from %s...", c.GetBaseURL())
+
+	body, err := c.doRequest("/api/ai500/list")
+	if err != nil {
+		return nil, fmt.Errorf("failed to request AI500 API: %w", err)
+	}
+
+	var response AI500Response
+	if err := json.Unmarshal(body, &response); err != nil {
+		return nil, fmt.Errorf("JSON parsing failed: %w", err)
+	}
+
+	if !response.Success {
+		return nil, fmt.Errorf("API returned failure status")
+	}
+
+	if len(response.Data.Coins) == 0 {
+		return nil, fmt.Errorf("coin list is empty")
+	}
+
+	// Set IsAvailable flag
+	coins := response.Data.Coins
+	for i := range coins {
+		coins[i].IsAvailable = true
+	}
+
+	log.Printf("✓ Successfully fetched %d AI500 coins", len(coins))
+	return coins, nil
+}
+
+// GetTopRatedCoins retrieves top N coins by score (sorted descending)
+func (c *Client) GetTopRatedCoins(limit int) ([]string, error) {
+	coins, err := c.GetAI500List()
+	if err != nil {
+		return nil, err
+	}
+
+	// Filter available coins
+	var availableCoins []CoinData
+	for _, coin := range coins {
+		if coin.IsAvailable {
+			availableCoins = append(availableCoins, coin)
+		}
+	}
+
+	if len(availableCoins) == 0 {
+		return nil, fmt.Errorf("no available coins")
+	}
+
+	// Sort by Score descending (bubble sort)
+	for i := 0; i < len(availableCoins); i++ {
+		for j := i + 1; j < len(availableCoins); j++ {
+			if availableCoins[i].Score < availableCoins[j].Score {
+				availableCoins[i], availableCoins[j] = availableCoins[j], availableCoins[i]
+			}
+		}
+	}
+
+	// Take top N
+	maxCount := limit
+	if len(availableCoins) < maxCount {
+		maxCount = len(availableCoins)
+	}
+
+	var symbols []string
+	for i := 0; i < maxCount; i++ {
+		symbol := NormalizeSymbol(availableCoins[i].Pair)
+		symbols = append(symbols, symbol)
+	}
+
+	return symbols, nil
+}
+
+// GetAvailableCoins retrieves all available coin symbols
+func (c *Client) GetAvailableCoins() ([]string, error) {
+	coins, err := c.GetAI500List()
+	if err != nil {
+		return nil, err
+	}
+
+	var symbols []string
+	for _, coin := range coins {
+		if coin.IsAvailable {
+			symbol := NormalizeSymbol(coin.Pair)
+			symbols = append(symbols, symbol)
+		}
+	}
+
+	if len(symbols) == 0 {
+		return nil, fmt.Errorf("no available coins")
+	}
+
+	return symbols, nil
+}
+
+// NormalizeSymbol normalizes coin symbol to XXXUSDT format
+func NormalizeSymbol(symbol string) string {
+	symbol = strings.TrimSpace(symbol)
+	symbol = strings.ToUpper(symbol)
+	if !strings.HasSuffix(symbol, "USDT") {
+		symbol = symbol + "USDT"
+	}
+	return symbol
+}