Separate scanner failure from a request that never reached the scanner

In a client-gated realtime scanner, correlate three layers in order: client or stage activity, the server's durable per-request attempt ledger, and the environment-specific engine proxy's request completions. A visible stage or user retry is not evidence that a request reached the engine.

If the client shows activity but both the attempt ledger and the correct proxy are empty, classify the block as pre-request and investigate readiness gating, encoding, and transport before blaming decoder quality. A ledger row plus aligned proxy and terminal engine telemetry can then distinguish no-read, parse failure, deadline, and queue pressure. This method requires correlation IDs and the correct environment path. Without client reason or score telemetry, it cannot identify which readiness predicate blocked the request.