fix: use request.user.sub instead of .id in users route

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

backend/src/routes/users.ts

@@ -102,7 +102,7 @@ const users: FastifyPluginAsync = async (fastify) => {
 
           // Look up hotel name and inviter name for the email
           const { rows: hotelRows } = await db.query('SELECT name FROM hotels WHERE id = $1', [hotelId])
-          const { rows: inviterRows } = await db.query('SELECT name FROM users WHERE id = $1', [request.user.id])
+          const { rows: inviterRows } = await db.query('SELECT name FROM users WHERE id = $1', [request.user.sub])
           const hotelName = hotelRows[0]?.name ?? 'отель'
           const invitedBy = inviterRows[0]?.name ?? 'Администратор'