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/public/openapi.json

@@ -2709,6 +2709,59 @@
         }
       }
     },
+    "/panel/api/inbounds/pushClientTraffics": {
+      "post": {
+        "tags": [
+          "Inbounds"
+        ],
+        "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.",
+        "operationId": "post_panel_api_inbounds_pushClientTraffics",
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "object"
+              },
+              "example": {
+                "masterGuid": "9f6c2d-…",
+                "traffics": [
+                  {
+                    "email": "alice",
+                    "up": 1048576,
+                    "down": 2097152
+                  }
+                ]
+              }
+            }
+          }
+        },
+        "responses": {
+          "200": {
+            "description": "Successful response",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "type": "object",
+                  "properties": {
+                    "success": {
+                      "type": "boolean"
+                    },
+                    "msg": {
+                      "type": "string"
+                    },
+                    "obj": {}
+                  }
+                },
+                "example": {
+                  "success": true
+                }
+              }
+            }
+          }
+        }
+      }
+    },
     "/panel/api/inbounds/{id}/fallbacks": {
       "get": {
         "tags": [