Replaces the per-session ``datatools-<ts>-<sid>.jsonl`` filename
with a single daily file ``datatools-YYYY-MM-DD.jsonl`` (local
date). Sessions on the same calendar day share a file via the
writer thread's per-batch open+append; multiple DataTools
instances running concurrently on the same day fan into the same
file (append-mode small writes are atomic on POSIX, safe-enough on
Windows under realistic load).
Drops the ``_LOG_PATH`` module global and the lock around it —
``audit_log_path()`` is now pure date math, recomputed on every
call so a session that crosses midnight follows the rollover into
the next day's file.
Adds ``_sweep_old_logs()`` invoked once per process at writer-
thread start. Deletes any ``datatools-*.jsonl`` whose mtime is
older than 7 days. The glob deliberately matches the legacy
per-session filename too, so users upgrading from the previous
build don't keep a permanent backlog of pre-retention files.
Event ``ts`` fields stay UTC; only the filename uses local date,
because users go looking for "today's log" on their wall clock.
Tests cover: daily filename shape, sweep removes stale files,
sweep keeps fresh files, sweep also clears legacy filenames.
Rollback: ``git revert HEAD`` restores the per-session filename
and removes the sweep. No data migration needed either way —
existing files keep working as JSONL.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Michael
b3ae913bb9