Malformed download URLs are rejected before the second request, error bodies are read only up to a bound, the telemetry summary keeps structural dispatch for duck-typed results, and the BMP magic now requires a valid DIB header. Docs and design are aligned with the implementation, and new test wording is neutral.
Zip construction and member reads now share one narrow boundary so corrupt BZIP2, LZMA and version fields cannot leak native exceptions. Non-success statuses are read before classification, text-bearing blocks require lines, the size cap and reasoning contract are pinned by tests that fail under mutation, and the per-page timing claim is corrected to the observed range.
Adds live-service and server-source evidence, structure contract, exception and resource boundaries, corrected breaker analysis, and the Codex review record.
Root-cause analysis from live MonkeyOCR probes: upload label is not detected, output carries no content, and deterministic bad-input 500s are treated as transient. Proposes parse_document with content-sniffed upload type and middle.json-only extraction.