Strict JSON file inputs reject a leading UTF-8 byte-order mark, but the
diagnostic was the parser's own message, which quotes the invisible U+FEFF
as the unexpected token: Unexpected token '', "{"invento"... is not
valid JSON. Editors such as Windows PowerShell 5.1 write that mark by
default, and nothing in the message showed it.
CLI JSON files (whole and streamed), Evidence and snapshot JSON files, and
process scenario files now report that the input begins with a UTF-8
byte-order mark and how to save it. Acceptance is unchanged.
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
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
gensokyo-dev