Node.js SaaS Error Tracking API: Backend Heartbeats, Optional React Source Maps

For a Node.js SaaS app, use an error tracking API for diagnosis, but detect a scheduled healthtech import that produces no result with a durable completion heartbeat for every expected backend run. The deciding constraint is rarely whether the tracker can capture a stack trace. It is whether the on-call engineer can distinguish an intentionally empty import from a scheduler, queue, credential, or downstream failure, while the platform owner can assign the resulting telemetry cost to the tenant and import class that caused it. TL;DR: keep exception events for diagnosis, but make a small, backen