fix: preserve real last_heartbeat when marking agent offline

The stale agent checker was calling Heartbeat() to mark agents offline,
which also updated last_heartbeat to the current time. This made agents
appear to have a recent heartbeat while showing status=offline.

Add SetStatus() method that updates only the status column without
touching last_heartbeat, so the dashboard correctly shows when the
agent last actually heartbeated.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: gcmsg

cmd/peerclawd/main.go

@@ -480,7 +480,8 @@ func main() {
 					}
 					for _, agentID := range staleAgents {
 						// Mark offline first so next tick won't pick it up again.
-						_, _ = regService.Heartbeat(ctx, agentID, agentcard.StatusOffline, nil)
+					// Use SetStatus (not Heartbeat) to preserve the real last_heartbeat timestamp.
+					_ = regService.SetStatus(ctx, agentID, agentcard.StatusOffline)
 
 						_ = repEngine.RecordEvent(ctx, agentID, "heartbeat_miss", "")
 						logger.Info("agent marked offline due to heartbeat timeout", "agent_id", agentID)

internal/registry/postgres.go

@@ -255,6 +255,21 @@ func (s *PostgresStore) UpdateHeartbeat(ctx context.Context, id string, status a
 	return nil
 }
 
+func (s *PostgresStore) UpdateStatus(ctx context.Context, id string, status agentcard.AgentStatus) error {
+	res, err := s.db.ExecContext(ctx,
+		"UPDATE agents SET status = $1 WHERE id = $2",
+		string(status), id,
+	)
+	if err != nil {
+		return err
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return fmt.Errorf("agent %s not found", id)
+	}
+	return nil
+}
+
 func (s *PostgresStore) UpdateMetadata(ctx context.Context, id string, metadata map[string]string) error {
 	if len(metadata) == 0 {
 		return nil

internal/registry/service.go

@@ -134,6 +134,11 @@ func (s *Service) Heartbeat(ctx context.Context, agentID string, status agentcar
 	return deadline, nil
 }
 
+// SetStatus updates only the agent's status without touching last_heartbeat.
+func (s *Service) SetStatus(ctx context.Context, agentID string, status agentcard.AgentStatus) error {
+	return s.store.UpdateStatus(ctx, agentID, status)
+}
+
 // GetAgent retrieves a single agent by ID.
 func (s *Service) GetAgent(ctx context.Context, agentID string) (*agentcard.Card, error) {
 	card, err := s.store.Get(ctx, agentID)

internal/registry/sqlite.go

@@ -281,6 +281,21 @@ func (s *SQLiteStore) UpdateHeartbeat(ctx context.Context, id string, status age
 	return nil
 }
 
+func (s *SQLiteStore) UpdateStatus(ctx context.Context, id string, status agentcard.AgentStatus) error {
+	res, err := s.db.ExecContext(ctx,
+		"UPDATE agents SET status = ? WHERE id = ?",
+		string(status), id,
+	)
+	if err != nil {
+		return err
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return fmt.Errorf("agent %s not found", id)
+	}
+	return nil
+}
+
 func (s *SQLiteStore) UpdateMetadata(ctx context.Context, id string, metadata map[string]string) error {
 	if len(metadata) == 0 {
 		return nil

internal/registry/store.go

@@ -55,6 +55,9 @@ type Store interface {
 	// UpdateHeartbeat updates the heartbeat timestamp and status of an agent.
 	UpdateHeartbeat(ctx context.Context, id string, status agentcard.AgentStatus) error
 
+	// UpdateStatus updates only the status of an agent without touching last_heartbeat.
+	UpdateStatus(ctx context.Context, id string, status agentcard.AgentStatus) error
+
 	// UpdateMetadata merges the provided metadata keys into the agent's existing metadata.
 	UpdateMetadata(ctx context.Context, id string, metadata map[string]string) error