Records the UID_2445 (vs SYNC_DATA1) identity decision, the sync-time age
snapshot, and the seeded reminder default; checks off the #14/#15 task lists.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Capture the full design for surfacing contact birthdays/anniversaries/custom
dates as auto-updating local calendars (Codeberg #15), plus the #14
prerequisite (per-calendar multiple default reminders). One local calendar per
type to reuse existing per-calendar color/visibility/reminder infra; one-way
mirror with field-level managed events keyed on contact LOOKUP_KEY.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
