`_append_entry` moved to `utils.atomic_json_write`, which dumps with
`ensure_ascii=False` through a utf-8 text handle. An argv token holding
surrogate-escaped bytes (a non-UTF-8 project path via os.fsdecode) makes
json.dump raise UnicodeEncodeError — a ValueError, so the `except OSError`
does not catch it and callers silently lose their registration.
Expose `ensure_ascii` on `atomic_json_write` (default unchanged) and pass
True at the ledger call site, restoring the previous json.dumps behaviour
while keeping mode=0o600. One round-trip test, red on base.
Follow-up to #109156.
teknium1
9d0d886c43