fix(routines): scan ±1-day activity files for cross-midnight anticipation triggers
The activity-anticipation dispatcher only loaded the current local day's
records, so a pre-alert for an early-morning D+1 activity was silently
missed when local_now was late on day D (and symmetric on the other side).
Scan yesterday/today/tomorrow gated by _ACTIVITY_ANTICIPATION_CROSSDAY_WINDOW_MINUTES
(default 120), and build start_dt from each record's own day.
Co-Authored-By: Codex <noreply@openai.com>