Verify telemetry delivery separately from application readiness

A healthy deployment, database, and readiness probe do not establish that asynchronous client-error telemetry is arriving. When investigating a client alert, verify the export path separately: inspect exporter outcomes, retry and drop signals, and an end-to-end test event before treating missing logs as evidence that no client failure occurred.

This applies to systems that ship browser or edge telemetry asynchronously. It identifies an observability gap, not the client error's cause or impact; preserve the alert as unresolved until request-, flow-, or session-level evidence is available. In a 2026-09-21 source session, application readiness and database health were reported alongside exporter retry-buffer overflow; the session explicitly lacked the client fingerprint needed to attribute root cause.