fix(cli): set end-of-day timestamp for bare dates in audit list --until

[amir-rezaei]

Description

This PR resolves issue #1181 by setting end-of-day timestamp (23:59:59.999999) for bare dates in _parse_date_filter (packages/taskdog-ui/src/taskdog/cli/commands/audit/list.py).

Details

• Fixes taskdog audit list --until YYYY-MM-DD dropping audit logs generated on the target date.

[Kohei-Wada]

Confirmed — datetime.fromisoformat("2026-07-25") has parsed bare dates since 3.7, so the except branch this relied on never ran and --until <date> dropped that day's logs. Fix is correct.

Two things before merging:

1. Tests are missing. Please add unit tests for _parse_date_filter covering: bare date with end_of_day=True → 23:59:59.999999; bare date with end_of_day=False → midnight; an explicit timestamp like 2026-07-25T09:00:00 left untouched even with end_of_day=True; and the fallback path. The first case must fail on the current code.
2. Formatting. ruff format --check wants to reformat one file on this branch — run make format.

Verified locally against current main: lint, typecheck and the full suite pass (ruff is 0.16 on main now, so please rebase).