fix(traffic): подтверждать свежесть статусов привязанных интерфейсов

lib/traffic-binding-status.test.ts

@@ -0,0 +1,9 @@
+import assert from "node:assert/strict"
+import { projectTrafficBindingStatus } from "./traffic-binding-status.js"
+const at=Date.parse("2026-10-12T12:00:00Z"),s=new Date(at).toISOString(),expiry=new Date(at+90_000).toISOString()
+assert.equal(projectTrafficBindingStatus("online",s,expiry,at),"online")
+assert.equal(projectTrafficBindingStatus("offline",s,expiry,at),"offline")
+assert.equal(projectTrafficBindingStatus("online",undefined,undefined,at),"unknown")
+assert.equal(projectTrafficBindingStatus("online",s,expiry,at+90_001),"unknown")
+assert.equal(projectTrafficBindingStatus("online",s,"bad",at),"unknown")
+console.log("binding status legacy/expiry projection tests ok")

lib/traffic-binding-status.ts

@@ -0,0 +1,6 @@
+export function projectTrafficBindingStatus(status: unknown, observedAt: unknown, expiresAt: unknown, now = Date.now()): "online" | "offline" | "unknown" {
+  if ((status !== "online" && status !== "offline") || typeof observedAt !== "string" || typeof expiresAt !== "string") return "unknown"
+  const observed = Date.parse(observedAt), expires = Date.parse(expiresAt)
+  if (!Number.isFinite(observed) || !Number.isFinite(expires) || observed >= expires || now > expires || observed > now + (expires-observed)/3) return "unknown"
+  return status
+}