GRASP-02: Proactive sync

Owned by graspVerified f35b4f9a4ed2normative specification

MUST proactively sync nostr events that match our acceptance criteria from other relays listed in relays tag of accepted git repository announcement, using both historic and live sync mechanisms.

MUST proactively sync missing git data from latest repo state announcement from other git servers listed in clone no less than every 1h.

MUST proactively fetch git data related to accepted git PR event or git PR update event no less than every 1h and serve from /refs/nostr/<event-id>.