probe: fast report stamps last-seen; snapshot TTL 900ms (V2.0.3)

internal/web/controller/agent.go

@@ -626,11 +626,16 @@ func probeStatIface(agentID int64) string {
 }
 
 // probeReport ingests one fast report (V2.0.1): a probe metrics
-// block and nothing else. It deliberately does NOT touch the
-// agent's last-seen stamp — liveness stays the 60 s heartbeat's
-// signal, and the traffic ledger's unseen-boot rule keeps measuring
-// reboots against heartbeat sightings exactly as before. Agents on
-// older masters never see this endpoint (404) and simply keep
+// block and nothing else. Since V2.0.3 it also touches the agent's
+// last-seen stamp, like every other report channel: the hub's
+// themes gate each batch on the node's last_seen being newer than
+// the last one they applied, so a metrics-only channel that never
+// advanced the stamp froze the public cards between the 10 s
+// traffic reports. Liveness now means "any report from the agent"
+// — all channels come from the same process — and the traffic
+// ledger's unseen-boot rule is unaffected: Record still receives
+// the pre-touch stamp, so gaps measure exactly as before. Agents
+// on older masters never see this endpoint (404) and simply keep
 // reporting metrics on the heartbeat; masters accept metrics on
 // either channel.
 func (a *AgentController) probeReport(c *gin.Context) {
@@ -644,9 +649,13 @@ func (a *AgentController) probeReport(c *gin.Context) {
 		ProbeMetrics *heartbeatProbeMetrics `json:"probeMetrics"`
 	}
 	_ = c.ShouldBindJSON(&req)
+	// The last-seen stamp as it stood before this report (see the
+	// heartbeat handler): captured before touchAgent overwrites it.
+	prevLastSeen := agent.LastSeen
+	a.touchAgent(uint(agent.Id), "")
 	if req.ProbeMetrics != nil {
 		a.updateAgentProbe(uint(agent.Id), nil, req.ProbeMetrics)
-		probe.Record(int64(agent.Id), probeSample(req.ProbeMetrics), agent.LastSeen)
+		probe.Record(int64(agent.Id), probeSample(req.ProbeMetrics), prevLastSeen)
 	}
 	jsonObj(c, gin.H{"message": "ok"}, nil)
 }