fix(backend): track traffic stats for federation port-forward tunnels (#204)

## Summary

- Fixed traffic statistics not being tracked for federation port-forward
tunnels (tunnelType=1) in Panel Peering mode
- Added `parsePeerShareIDFromFederationTunnelName()` to extract shareID
from tunnel names matching `Share-{shareId}-Port-{port}` pattern
- Added `processPeerShareFlowFromForward()` to update
`peer_share.current_flow` when forward traffic belongs to a federation
port-forward tunnel
- Added regression test
`TestProcessFlowItemTracksPeerShareFlowForFederationPortForward`

## Root Cause

Federation + tunnel type=2 (隧道转发) traffic uses service names
`fed_svc_{runtimeID}` → correctly routed to `processPeerShareFlow()` →
`peer_share.current_flow` updated.

Federation + tunnel type=1 (端口转发) traffic uses regular forward service
names `{forwardId}_{userId}_{userTunnelId}` → only `AddFlow()` called →
`peer_share.current_flow` NOT updated → shared flow stats remain 0.

## Test Plan

- [x] `go test ./internal/http/handler -run
'TestProcessFlowItemTracksPeerShareFlow'` passes
- [x] `go test ./internal/http/handler` passes
- [x] `go test ./...` passes
- [x] `make build` succeeds

go-backend/internal/http/handler/flow_policy.go

@@ -40,6 +40,7 @@ func (h *Handler) processFlowItem(item flowItem) {
 	if ok {
 		inFlow, outFlow := h.scaleFlowByTunnel(forwardID, item.D, item.U)
 		_ = h.repo.AddFlow(forwardID, userID, userTunnelID, inFlow, outFlow)
+		h.processPeerShareFlowFromForward(forwardID, item)
 
 		if userTunnelID > 0 {
 			h.enforceFlowPolicies(userID, userTunnelID)
@@ -87,6 +88,23 @@ func parsePeerShareRuntimeServiceID(serviceName string) (int64, bool) {
 	return runtimeID, true
 }
 
+func parsePeerShareIDFromFederationTunnelName(tunnelName string) (int64, bool) {
+	tunnelName = strings.TrimSpace(tunnelName)
+	if !strings.HasPrefix(tunnelName, "Share-") {
+		return 0, false
+	}
+	raw := strings.TrimPrefix(tunnelName, "Share-")
+	idx := strings.Index(raw, "-Port-")
+	if idx <= 0 {
+		return 0, false
+	}
+	shareID, err := strconv.ParseInt(raw[:idx], 10, 64)
+	if err != nil || shareID <= 0 {
+		return 0, false
+	}
+	return shareID, true
+}
+
 func (h *Handler) processPeerShareFlow(runtimeID int64, item flowItem) {
 	if h == nil || h.repo == nil || runtimeID <= 0 {
 		return
@@ -113,6 +131,44 @@ func (h *Handler) processPeerShareFlow(runtimeID int64, item flowItem) {
 	h.enforcePeerShareFlowLimit(share.ID)
 }
 
+func (h *Handler) processPeerShareFlowFromForward(forwardID int64, item flowItem) {
+	if h == nil || h.repo == nil || forwardID <= 0 {
+		return
+	}
+	forward, err := h.getForwardRecord(forwardID)
+	if err != nil || forward == nil {
+		return
+	}
+	tunnel, err := h.getTunnelRecord(forward.TunnelID)
+	if err != nil || tunnel == nil {
+		return
+	}
+	tunnelName, err := h.repo.GetTunnelName(forward.TunnelID)
+	if err != nil {
+		return
+	}
+	shareID, ok := parsePeerShareIDFromFederationTunnelName(tunnelName)
+	if !ok {
+		return
+	}
+
+	delta := item.D + item.U
+	if delta <= 0 {
+		return
+	}
+
+	_ = h.repo.AddPeerShareCurrentFlow(shareID, delta)
+
+	share, err := h.repo.GetPeerShare(shareID)
+	if err != nil || share == nil {
+		return
+	}
+	if !isPeerShareFlowExceeded(share) {
+		return
+	}
+	h.enforcePeerShareFlowLimit(share.ID)
+}
+
 func (h *Handler) enforcePeerShareFlowLimit(shareID int64) {
 	if h == nil || h.repo == nil || shareID <= 0 {
 		return

go-backend/internal/http/handler/flow_policy_federation_test.go

@@ -2,6 +2,7 @@ package handler
 
 import (
 	"path/filepath"
+	"strconv"
 	"testing"
 	"time"
 
@@ -61,3 +62,71 @@ func TestProcessFlowItemTracksPeerShareFlowAndEnforcesLimit(t *testing.T) {
 		t.Fatalf("expected runtime status=0 after limit enforcement, got %d", runtime.Status)
 	}
 }
+
+func TestProcessFlowItemTracksPeerShareFlowForFederationPortForward(t *testing.T) {
+	r, err := repo.Open(filepath.Join(t.TempDir(), "panel-forward.db"))
+	if err != nil {
+		t.Fatalf("open repo: %v", err)
+	}
+	defer r.Close()
+
+	now := time.Now().UnixMilli()
+	if err := r.CreatePeerShare(&repo.PeerShare{
+		Name:           "forward-share",
+		NodeID:         1,
+		Token:          "forward-share-token",
+		MaxBandwidth:   0,
+		CurrentFlow:    0,
+		PortRangeStart: 30000,
+		PortRangeEnd:   30010,
+		IsActive:       1,
+		CreatedTime:    now,
+		UpdatedTime:    now,
+	}); err != nil {
+		t.Fatalf("create peer share: %v", err)
+	}
+	share, err := r.GetPeerShareByToken("forward-share-token")
+	if err != nil || share == nil {
+		t.Fatalf("load peer share: %v", err)
+	}
+
+	if err := r.DB().Exec(`
+		INSERT INTO user(id, user, pwd, role_id, exp_time, flow, in_flow, out_flow, flow_reset_time, num, created_time, updated_time, status)
+		VALUES(2, 'u2', 'x', 1, ?, 99999, 0, 0, 1, 1, ?, ?, 1)
+	`, now+24*60*60*1000, now, now).Error; err != nil {
+		t.Fatalf("insert user: %v", err)
+	}
+
+	tunnelName := "Share-" + strconv.FormatInt(share.ID, 10) + "-Port-30001"
+	if err := r.DB().Exec(`
+		INSERT INTO tunnel(id, name, traffic_ratio, type, protocol, flow, created_time, updated_time, status, in_ip, inx)
+		VALUES(1, ?, 1.0, 1, 'tls', 1, ?, ?, 1, NULL, 0)
+	`, tunnelName, now, now).Error; err != nil {
+		t.Fatalf("insert tunnel: %v", err)
+	}
+
+	if err := r.DB().Exec(`
+		INSERT INTO user_tunnel(id, user_id, tunnel_id, speed_id, num, flow, in_flow, out_flow, flow_reset_time, exp_time, status)
+		VALUES(10, 2, 1, NULL, 1, 99999, 0, 0, 1, ?, 1)
+	`, now+24*60*60*1000).Error; err != nil {
+		t.Fatalf("insert user_tunnel: %v", err)
+	}
+
+	if err := r.DB().Exec(`
+		INSERT INTO forward(id, user_id, user_name, name, tunnel_id, remote_addr, strategy, in_flow, out_flow, created_time, updated_time, status, inx)
+		VALUES(20, 2, 'u2', 'f20', 1, '1.1.1.1:443', 'fifo', 0, 0, ?, ?, 1, 0)
+	`, now, now).Error; err != nil {
+		t.Fatalf("insert forward: %v", err)
+	}
+
+	h := &Handler{repo: r}
+	h.processFlowItem(flowItem{N: "20_2_10", U: 120, D: 80})
+
+	updatedShare, err := r.GetPeerShare(share.ID)
+	if err != nil || updatedShare == nil {
+		t.Fatalf("reload share: %v", err)
+	}
+	if updatedShare.CurrentFlow != 200 {
+		t.Fatalf("expected current_flow=200, got %d", updatedShare.CurrentFlow)
+	}
+}