安全加固：LLM 会话按 (bot,peer) 隔离+历史上限50条，LLM 入队按 (bot,from_node) 限流(60s内5条)，瓦片磁盘缓存单源配额(3000文件/300MB 按mtime淘汰)，签到墙读接口限速+全站每日1000条封顶，敏感数据落盘 AES-256-GCM 加密(MESH_SECRET_KEY, 兼容明文迁移)，admin 改密需验证当前密码+pwd_version 会话撤销，后端 v1.5.0

internal/agents/sign/sign.go

@@ -25,12 +25,16 @@ import (
 type SignStore interface {
 	CreateSign(nodeID string, longName, shortName *string, signText string, signTime time.Time) (*storepkg.SignRecord, error)
 	HasSignedOnDay(nodeID string, day time.Time) (bool, error)
+	CountSignsOnDay(day time.Time) (int64, error)
 	GetNodeInfo(nodeID string) (*storepkg.NodeInfoRecord, error)
 	CountSigns(opts storepkg.ListOptions) (int64, error)
 	CountSignsByDay(opts storepkg.ListOptions) ([]storepkg.SignDayCount, error)
 	ListSigns(opts storepkg.ListOptions) ([]storepkg.SignRecord, error)
 }
 
+// maxSignsPerDay 全站每日签到记录总量封顶,防止伪造节点刷公开签到墙。
+const maxSignsPerDay = 1000
+
 // Tool 是签到工具。
 type Tool struct {
 	enabled bool
@@ -164,6 +168,15 @@ func (t *Tool) executeSign(ctx context.Context, params signParams, runtime agent
 		return fmt.Sprintf("%s 今天已经签到过了，每个节点每天只能签到一次。", displayName(node)), nil
 	}
 
+	// 全站每日签到总量封顶,防止伪造海量节点号刷爆公开签到墙。
+	todayCount, err := t.store.CountSignsOnDay(now)
+	if err != nil {
+		return fmt.Sprintf("签到失败：统计今日签到数时出错：%v", err), nil
+	}
+	if todayCount >= maxSignsPerDay {
+		return "今日签到人数已达上限，请明天再来。", nil
+	}
+
 	signText := buildSignText(params)
 	if signText == "" {
 		// 结构化字段缺失时回退到用户原始文本