ingestExternalMonitoringEvents

Ingest monitoring spans produced by an EXTERNAL system (e.g. an integration middleware), so the Integration Hub is the central monitoring point and the cross-system event trace spans both the external system and epilot's own processing.

Each span is validated, assigned a server-controlled EXTERNAL_* taxonomy code derived from its level (the client never supplies a code — this marks provenance and prevents spoofing an epilot code), has its use_case_slug resolved against the integration's configured use cases, and is republished onto the same monitoring event bus as epilot's own spans — so external spans are first-class to the trace view, stats, alerting and digests.

Spans link to the epilot trace via correlation_id (the trace id): the middleware must stamp the same correlation_id here and on the event it forwards to the inbound endpoint. Invalid spans in a batch are reported per-item and do not fail the whole batch.