Resource-exhausted OCR responses do not identify the exhausted quota

An OCR provider's RESOURCE_EXHAUSTED response identifies the failure category, but a generic message without a quota metric does not establish which customer quota was exceeded or whether provider capacity is constrained. Separate text detection from downstream extraction, inspect per-image errors even when the outer HTTP request succeeds, and compare recorded failures with project-specific quota counters before changing billing or rotating credentials. Successful downstream extraction does not prove the upstream OCR stage is healthy. This method applies to multi-stage provider pipelines; it does not diagnose any particular account without its quota and service-health evidence.