fix(server/reward): TG bot 回复区分已领取/未加入两态 + 按 Telegram language_code 中英双语

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01P9G7E3wmAYL9KeYCVZVsqu

server/internal/reward/telegram.go

@@ -91,32 +91,44 @@ func (s *Service) ConsumeTelegramToken(ctx context.Context, token string) (int64
 	return id, ok, nil
 }
 
+// ClaimResult 是 ClaimTelegram 的结果三态,供上层(handler)按态回不同文案。
+type ClaimResult int
+
+const (
+	ClaimGranted   ClaimResult = iota // 发放成功
+	ClaimAlready                      // 已领取过(本账户或该 telegram_id)
+	ClaimNotMember                    // 不在频道
+)
+
 // ClaimTelegram: 真是频道成员则一次性发 TgDays 天(source='task'),唯一守卫防重复领取
 // (同 userID 或同 telegramID 只能成功一次)。
-func (s *Service) ClaimTelegram(ctx context.Context, userID int64, telegramID string) (bool, error) {
+func (s *Service) ClaimTelegram(ctx context.Context, userID int64, telegramID string) (ClaimResult, error) {
 	member, err := s.checker.IsMember(ctx, s.tg.channel, telegramID)
-	if err != nil || !member {
-		return false, err
+	if err != nil {
+		return ClaimNotMember, err
+	}
+	if !member {
+		return ClaimNotMember, nil
 	}
 	tx, err := s.db.BeginTx(ctx, &sql.TxOptions{})
 	if err != nil {
-		return false, err
+		return ClaimNotMember, err
 	}
 	defer func() { _ = tx.Rollback() }()
 	now := s.now()
 	if err := s.st.InsertClaimTx(ctx, tx, userID, "telegram_join", telegramID, s.cfg.TgDays, now); err != nil {
 		if err == ErrClaimExists {
-			return false, nil // 已领过(本账户 or 该 tgid)
+			return ClaimAlready, nil // 已领过(本账户 or 该 tgid)
 		}
-		return false, err
+		return ClaimNotMember, err
 	}
 	if _, _, err := s.g.GrantRewardTx(ctx, tx, userID, s.cfg.TgDays, "task", "task_telegram_join", "tg:"+telegramID); err != nil {
-		return false, err
+		return ClaimNotMember, err
 	}
 	if err := tx.Commit(); err != nil {
-		return false, err
+		return ClaimNotMember, err
 	}
-	return true, nil
+	return ClaimGranted, nil
 }
 
 // apiChecker 是 ChatMemberChecker 的默认生产实现:打 Telegram getChatMember。