feat: init nofxi - AI Trading Agent module

NOFXi — Your AI Trading Agent, built on NOFX.

Architecture:
- Agent Core: intent routing, conversation memory, trade confirmation
- Memory: SQLite (trades, conversations, preferences, strategies)
- Thinking: LLM client (OpenAI/claw402/DeepSeek compatible)
- Execution: Bridge to NOFX trader engine (9 exchanges)
- Perception: Market monitor, price alerts, anomaly detection
- Interaction: Telegram bot + REST API + OpenAI-compatible endpoint

Features:
- Natural language trading (中英文)
- /buy /sell /analyze /watch /alert /positions /balance
- Daily P/L reports, portfolio risk checks
- Trade confirmation flow (safety first)
- Price polling and alert notifications

nofxi/internal/interaction/telegram.go

@@ -0,0 +1,128 @@
+package interaction
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+
+	tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api/v5"
+)
+
+// MessageHandler is called for each incoming message.
+type MessageHandler func(ctx context.Context, userID int64, text string) (string, error)
+
+// TelegramBot wraps the Telegram Bot API.
+type TelegramBot struct {
+	bot        *tgbotapi.BotAPI
+	handler    MessageHandler
+	allowedIDs map[int64]bool // Empty = allow all
+	logger     *slog.Logger
+}
+
+// NewTelegramBot creates a new Telegram bot.
+func NewTelegramBot(token string, allowedIDs []int64, handler MessageHandler, logger *slog.Logger) (*TelegramBot, error) {
+	bot, err := tgbotapi.NewBotAPI(token)
+	if err != nil {
+		return nil, fmt.Errorf("create bot: %w", err)
+	}
+
+	allowed := make(map[int64]bool)
+	for _, id := range allowedIDs {
+		allowed[id] = true
+	}
+
+	logger.Info("telegram bot authorized", "username", bot.Self.UserName)
+
+	return &TelegramBot{
+		bot:        bot,
+		handler:    handler,
+		allowedIDs: allowed,
+		logger:     logger,
+	}, nil
+}
+
+// Start begins polling for updates. Blocks until context is cancelled.
+func (t *TelegramBot) Start(ctx context.Context) error {
+	u := tgbotapi.NewUpdate(0)
+	u.Timeout = 60
+
+	updates := t.bot.GetUpdatesChan(u)
+
+	t.logger.Info("telegram bot started, listening for messages...")
+
+	for {
+		select {
+		case <-ctx.Done():
+			t.bot.StopReceivingUpdates()
+			t.logger.Info("telegram bot stopped")
+			return nil
+		case update := <-updates:
+			if update.Message == nil {
+				continue
+			}
+			go t.handleUpdate(ctx, update)
+		}
+	}
+}
+
+func (t *TelegramBot) handleUpdate(ctx context.Context, update tgbotapi.Update) {
+	msg := update.Message
+	userID := msg.From.ID
+
+	// Access control
+	if len(t.allowedIDs) > 0 && !t.allowedIDs[userID] {
+		t.logger.Warn("unauthorized user", "user_id", userID, "username", msg.From.UserName)
+		t.sendText(msg.Chat.ID, "⛔ Unauthorized. Contact the admin to get access.")
+		return
+	}
+
+	text := msg.Text
+	if text == "" {
+		return
+	}
+
+	t.logger.Info("received message",
+		"user_id", userID,
+		"username", msg.From.UserName,
+		"text", text,
+	)
+
+	// Send "typing" indicator
+	typing := tgbotapi.NewChatAction(msg.Chat.ID, tgbotapi.ChatTyping)
+	t.bot.Send(typing)
+
+	// Process message
+	response, err := t.handler(ctx, userID, text)
+	if err != nil {
+		t.logger.Error("handle message", "error", err)
+		response = fmt.Sprintf("⚠️ Error: %v", err)
+	}
+
+	t.sendMarkdown(msg.Chat.ID, response)
+}
+
+func (t *TelegramBot) sendText(chatID int64, text string) {
+	msg := tgbotapi.NewMessage(chatID, text)
+	if _, err := t.bot.Send(msg); err != nil {
+		t.logger.Error("send message", "error", err)
+	}
+}
+
+func (t *TelegramBot) sendMarkdown(chatID int64, text string) {
+	msg := tgbotapi.NewMessage(chatID, text)
+	msg.ParseMode = tgbotapi.ModeMarkdown
+
+	if _, err := t.bot.Send(msg); err != nil {
+		// Retry without markdown if parsing fails
+		t.logger.Warn("markdown send failed, retrying plain", "error", err)
+		t.sendText(chatID, text)
+	}
+}
+
+// SendNotification sends a proactive message to a user.
+func (t *TelegramBot) SendNotification(userID int64, text string) error {
+	msg := tgbotapi.NewMessage(userID, text)
+	msg.ParseMode = tgbotapi.ModeMarkdown
+	_, err := t.bot.Send(msg)
+	return err
+}