feat(node-sync): push global client usage to nodes for display and local enforcement

A client attached to several panels has one aggregated row on each
master, but a node only ever saw its local share: the node UI
under-reported usage, and the node kept serving a client whose
cross-panel total had already exceeded its quota — the master's disable
push doesn't kill established connections unless the node restarts xray
itself.

Masters now push their aggregated per-client counters to each node from
NodeTrafficSyncJob (throttled, scoped to the clients that node hosts).
The node stores them in the new client_global_traffics side table keyed
by (masterGuid, email), overwritten on every push so a master-side
reset propagates, and:

- overlays max(local, pushed) onto UI read paths (slim inbound list,
  inbound detail, clients list, WS stats, per-email lookups). The full
  /panel/api/inbounds/list stays un-overlaid on purpose: it doubles as
  the traffic snapshot masters poll, and overlaying it would corrupt
  every master's delta accounting;
- trips disableInvalidClients when any master's pushed total exceeds
  the client's quota, so the existing RestartXrayOnClientDisable flow
  disconnects the client locally;
- clears the side rows on traffic reset, auto-renew, and client
  delete, keeping a renewed quota window clean.

Supersedes #5204, which folded pushed globals into client_traffics and
compensated with read-back baselines — that double-counted first-sight
emails and could not work with several masters sharing one node.

internal/web/service/client_crud.go

@@ -411,6 +411,9 @@ func (s *ClientService) Delete(inboundSvc *InboundService, id int, keepTraffic b
 		if err := db.Where("email = ?", existing.Email).Delete(&xray.ClientTraffic{}).Error; err != nil {
 			return needRestart, err
 		}
+		if err := clearGlobalTraffic(db, existing.Email); err != nil {
+			return needRestart, err
+		}
 		if err := db.Where("client_email = ?", existing.Email).Delete(&model.InboundClientIps{}).Error; err != nil {
 			return needRestart, err
 		}
@@ -550,6 +553,9 @@ func (s *ClientService) DeleteByEmail(inboundSvc *InboundService, email string,
 		if err := db.Where("email = ?", email).Delete(&xray.ClientTraffic{}).Error; err != nil {
 			return needRestart, err
 		}
+		if err := clearGlobalTraffic(db, email); err != nil {
+			return needRestart, err
+		}
 		if err := db.Where("client_email = ?", email).Delete(&model.InboundClientIps{}).Error; err != nil {
 			return needRestart, err
 		}