feat: KKT dto_device_id — multiple KKTs per DTO instance

- EquipmentPage: added "ID устройства в ДТО" field (config.dto_device_id),
  shown on device card as #1
- api.ts: typed config.dto_device_id in WorkstationDevice

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

backend/src/routes/workstations.ts

@@ -302,6 +302,7 @@ const workstationRoutes: FastifyPluginAsync = async (fastify) => {
             dto_port: device.dto_port,
             dto_user: device.config?.dto_user,
             dto_pass: device.config?.dto_pass,
+            dto_device_id: device.config?.dto_device_id,
           },
         }) as { ok: boolean; error?: string; message?: string }
         return result