Add TravelLine pull integration for NetUP: capture endpoint + tl_token

- New /travelline route: accepts all NetUP polls, logs them to in-memory
  ring buffer (GET /travelline/_log to inspect), responds with active
  reservations in a generic PMS format
- Migration 007: adds tl_token column to netup_settings
- PATCH netup/settings now saves tl_token; GET returns it
- TvWelcomePage: new TravelLine section with read-only API URL + copy
  button and token input field

Setup in NetUP: Integration type = TravelLine,
API URL = https://api.hotelsync.ru/travelline, Token = <tl_token>

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

backend/src/app.ts

@@ -16,6 +16,7 @@ import housekeepingRoutes from './routes/housekeeping'
 import channelsRoutes    from './routes/channels'
 import usersRoutes       from './routes/users'
 import netupRoutes       from './routes/netup'
+import travellineRoutes  from './routes/travelline'
 
 export async function buildApp() {
   const fastify = Fastify({
@@ -73,6 +74,7 @@ export async function buildApp() {
   await fastify.register(channelsRoutes)
   await fastify.register(usersRoutes)
   await fastify.register(netupRoutes)
+  await fastify.register(travellineRoutes)
 
   return fastify
 }