fix: register @fastify/websocket globally so /ws/agent route works

setupAgentWsRoute was called outside the encapsulated wsRoutes plugin
scope where @fastify/websocket was registered. Register the plugin at
the root level and convert setupAgentWsRoute to FastifyPluginAsync.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/src/agent-ws.ts

@@ -3,7 +3,7 @@
  * Агенты подключаются по wss://api.hotelsync.ru/ws/agent
  * и остаются подключёнными для получения команд
  */
-import { FastifyInstance } from 'fastify'
+import { FastifyInstance, FastifyPluginAsync } from 'fastify'
 import type { SocketStream } from '@fastify/websocket'
 import { WebSocket } from 'ws'
 import { db } from './db'
@@ -71,7 +71,7 @@ async function markOnline(workstationId: string, ip?: string) {
 }
 
 // Регистрируем route для WebSocket агентов
-export function setupAgentWsRoute(fastify: FastifyInstance) {
+export const setupAgentWsRoute: FastifyPluginAsync = async (fastify) => {
   fastify.get('/ws/agent', { websocket: true }, async (connection: SocketStream, req) => {
     const socket = connection.socket as AgentSocket
 

backend/src/app.ts

@@ -10,6 +10,7 @@ import { join } from 'path'
 import { config } from './config'
 import './types' // side-effect: augments fastify types
 
+import fastifyWebsocket   from '@fastify/websocket'
 import wsRoutes          from './routes/ws'
 import authRoutes        from './routes/auth'
 import hotelsRoutes      from './routes/hotels'
@@ -53,6 +54,9 @@ export async function buildApp() {
   const uploadsDir = process.env.UPLOADS_DIR ?? join(process.cwd(), 'uploads')
   await fastify.register(staticFiles, { root: uploadsDir, prefix: '/uploads/' })
 
+  // ── WebSocket ──────────────────────────────────────────────────────────────
+  await fastify.register(fastifyWebsocket)
+
   // ── Security ───────────────────────────────────────────────────────────────
   await fastify.register(helmet, { contentSecurityPolicy: false, crossOriginResourcePolicy: { policy: 'cross-origin' } })
 
@@ -114,7 +118,7 @@ export async function buildApp() {
   await fastify.register(loyaltyRoutes)
   await fastify.register(chatRoutes)
   await fastify.register(workstationRoutes)
-  setupAgentWsRoute(fastify)
+  await fastify.register(setupAgentWsRoute)
 
   startJobs()
 

backend/src/routes/ws.ts

@@ -1,5 +1,4 @@
 import { FastifyPluginAsync } from 'fastify'
-import fastifyWebsocket from '@fastify/websocket'
 import type { SocketStream } from '@fastify/websocket'
 import type { RawData } from 'ws'
 
@@ -18,8 +17,6 @@ export function broadcast(hotelSlug: string, message: object) {
 const PING_INTERVAL_MS = 25_000 // ping every 25s — keeps nginx proxy_read_timeout alive
 
 const ws: FastifyPluginAsync = async (fastify) => {
-  await fastify.register(fastifyWebsocket)
-
   fastify.get<{ Querystring: { hotel?: string } }>(
     '/ws',
     { websocket: true },