Bind telemetry queries to environment and event grain

General lesson: before concluding that recent telemetry is missing, verify both the physical environment target and the aggregation grain. A valid query against the wrong environment can be internally consistent but irrelevant. An all-time COUNT(DISTINCT entity_id) can also stay unchanged while many new attempts arrive for one existing entity. For operational diagnostics, include the target identity, a bounded created_at window, MAX(created_at), attempt count, distinct-entity count, and the canonical success field.

Applicability: staging/production data isolation, canaries, repeated scans, retries, and any event table where one entity can emit multiple attempts. Limit: this method proves persistence and query visibility; it does not prove browser-side events that never reached the server.