🔔 feat: Add subscription-aware quota notifications and update UI copy

Routes quota alerts through a subscription-specific check when billing from subscriptions, preventing wallet-based thresholds from triggering false warnings.
Updates the notification settings description and localization keys to clarify that both wallet and subscription balances are monitored.

service/quota.go

@@ -556,3 +556,51 @@ func checkAndSendQuotaNotify(relayInfo *relaycommon.RelayInfo, quota int, preCon
 		}
 	})
 }
+
+func checkAndSendSubscriptionQuotaNotify(relayInfo *relaycommon.RelayInfo) {
+	gopool.Go(func() {
+		if relayInfo == nil {
+			return
+		}
+		if relayInfo.SubscriptionId == 0 || relayInfo.SubscriptionAmountTotal <= 0 {
+			return
+		}
+
+		userSetting := relayInfo.UserSetting
+		threshold := common.QuotaRemindThreshold
+		if userSetting.QuotaWarningThreshold != 0 {
+			threshold = int(userSetting.QuotaWarningThreshold)
+		}
+
+		usedAfter := relayInfo.SubscriptionAmountUsedAfterPreConsume + relayInfo.SubscriptionPostDelta
+		remaining := relayInfo.SubscriptionAmountTotal - usedAfter
+		if remaining >= int64(threshold) {
+			return
+		}
+
+		prompt := "您的订阅额度即将用尽"
+		topUpLink := fmt.Sprintf("%s/console/topup", system_setting.ServerAddress)
+
+		var content string
+		var values []interface{}
+		notifyType := userSetting.NotifyType
+		if notifyType == "" {
+			notifyType = dto.NotifyTypeEmail
+		}
+
+		if notifyType == dto.NotifyTypeBark {
+			content = "{{value}}，剩余额度：{{value}}，请及时充值"
+			values = []interface{}{prompt, logger.FormatQuota(int(remaining))}
+		} else if notifyType == dto.NotifyTypeGotify {
+			content = "{{value}}，当前剩余额度为 {{value}}，请及时充值。"
+			values = []interface{}{prompt, logger.FormatQuota(int(remaining))}
+		} else {
+			content = "{{value}}，当前剩余额度为 {{value}}，为了不影响您的使用，请及时充值。<br/>充值链接：<a href='{{value}}'>{{value}}</a>"
+			values = []interface{}{prompt, logger.FormatQuota(int(remaining)), topUpLink, topUpLink}
+		}
+
+		if err := NotifyUser(relayInfo.UserId, relayInfo.UserEmail, relayInfo.UserSetting, dto.NewNotify(dto.NotifyTypeQuotaExceed, prompt, content, values)); err != nil {
+			common.SysError(fmt.Sprintf("failed to send subscription quota notify to user %d: %s", relayInfo.UserId, err.Error()))
+		}
+	})
+}