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.

frontend/src/pages/api-docs/endpoints.ts

@@ -205,6 +205,17 @@ export const sections: readonly Section[] = [
           { name: 'data', in: 'body (form)', type: 'string', desc: 'JSON-encoded inbound payload.' },
         ],
       },
+      {
+        method: 'POST',
+        path: '/panel/api/inbounds/pushClientTraffics',
+        summary: 'Receive a master panel\'s aggregated per-client usage, keyed by the master\'s GUID. Stored in a side table used only for the UI display overlay and local quota enforcement — never folded into the local counters that masters poll, so delta accounting stays intact. Called panel-to-panel by the node traffic sync job.',
+        params: [
+          { name: 'masterGuid', in: 'body (json)', type: 'string', desc: 'Stable GUID of the pushing master panel.' },
+          { name: 'traffics', in: 'body (json)', type: 'object[]', desc: 'Client traffic rows; only email/up/down are read.' },
+        ],
+        body: '{\n  "masterGuid": "9f6c2d-…",\n  "traffics": [\n    { "email": "alice", "up": 1048576, "down": 2097152 }\n  ]\n}',
+        response: '{\n  "success": true\n}',
+      },
       {
         method: 'GET',
         path: '/panel/api/inbounds/:id/fallbacks',