Reopen closed fabric peer sessions

agents/rap-node-agent/internal/mesh/client.go

@@ -293,6 +293,18 @@ func (p *FabricSessionPump) Errors() <-chan error {
 	return p.errors
 }
 
+func (p *FabricSessionPump) Closed() bool {
+	if p == nil {
+		return true
+	}
+	select {
+	case <-p.done:
+		return true
+	default:
+		return false
+	}
+}
+
 func (p *FabricSessionPump) Close() error {
 	if p == nil {
 		return nil

agents/rap-node-agent/internal/mesh/fabric_session_manager.go

@@ -35,9 +35,13 @@ func (m *FabricSessionPeerManager) Get(ctx context.Context, target FabricSession
 	}
 	m.mu.Lock()
 	if pump := m.sessions[key]; pump != nil {
+		if pump.Closed() {
+			delete(m.sessions, key)
+		} else {
 			m.mu.Unlock()
 			return pump, nil
 		}
+	}
 	m.mu.Unlock()
 
 	session, _, err := NewClient(target.BaseURL).OpenFabricSession(ctx, target.Options)
@@ -48,10 +52,14 @@ func (m *FabricSessionPeerManager) Get(ctx context.Context, target FabricSession
 
 	m.mu.Lock()
 	if existing := m.sessions[key]; existing != nil {
+		if existing.Closed() {
+			delete(m.sessions, key)
+		} else {
 			m.mu.Unlock()
 			_ = pump.Close()
 			return existing, nil
 		}
+	}
 	if m.sessions == nil {
 		m.sessions = map[string]*FabricSessionPump{}
 	}

agents/rap-node-agent/internal/mesh/fabric_session_manager_test.go

@@ -117,6 +117,54 @@ func TestFabricSessionPeerManagerClosePeerReopens(t *testing.T) {
 	}
 }
 
+func TestFabricSessionPeerManagerReopensClosedPump(t *testing.T) {
+	var opened int
+	server := httptest.NewServer(Server{
+		Local:                PeerIdentity{ClusterID: "cluster-1", NodeID: "node-a"},
+		FabricSessionEnabled: true,
+		FabricSessionLogger: func(entry FabricSessionEventLogEntry) {
+			if entry.Event == "fabric_session_websocket_opened" {
+				opened++
+			}
+		},
+	}.Handler())
+	defer server.Close()
+
+	manager := NewFabricSessionPeerManager()
+	defer manager.Close()
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+	target := FabricSessionPeerTarget{
+		PeerID:  "node-a",
+		BaseURL: server.URL,
+		Options: FabricSessionDialOptions{
+			Token:   "rap_fsn_manager_closed",
+			Timeout: time.Second,
+		},
+	}
+
+	first, err := manager.Get(ctx, target)
+	if err != nil {
+		t.Fatalf("first get: %v", err)
+	}
+	if err := first.Close(); err != nil {
+		t.Fatalf("close first pump: %v", err)
+	}
+	if !first.Closed() {
+		t.Fatal("first pump should report closed")
+	}
+	second, err := manager.Get(ctx, target)
+	if err != nil {
+		t.Fatalf("second get: %v", err)
+	}
+	if first == second {
+		t.Fatal("manager reused closed pump")
+	}
+	if opened != 2 {
+		t.Fatalf("opened sessions = %d, want 2", opened)
+	}
+}
+
 func TestFabricSessionPeerManagerRejectsIncompleteTarget(t *testing.T) {
 	manager := NewFabricSessionPeerManager()
 	_, err := manager.Get(context.Background(), FabricSessionPeerTarget{PeerID: "node-a"})

docs/architecture/DISTRIBUTED_FABRIC_NODE_PROTOCOL_PLAN.md

@@ -287,6 +287,8 @@ rollout independently controllable.
 When the VPN fabric-session switch is enabled, node-agent now attempts to use a
 long-lived peer session for gateway packet transport and falls back to the
 existing HTTP production envelope path when the peer session is unavailable.
+Peer session reuse now evicts closed pumps before reuse, so failed WebSocket
+sessions can be reopened on the next transport acquisition.
 
 Deliverables: