Stream large CLI JSON files through a strict UTF-8 decoder and standard JSON parser using the same admitted regular-file handle. Preserve native parsing for small inputs, typed malformed-input/resource/access-denied errors, cancellation, and complete Evidence.
Verified with focused public CLI regressions, a 768 MB whitespace-padded valid request, and the Windows native decoder boundary. Individual strings and the assembled object graph remain subject to native runtime limits. All 27 final-head checks passed.
Refs #1331