Status: IN
Live projections achieve exactly-once processing semantics through three reinforcing mechanisms: position-guarded deduplication prevents double-processing during overlapping catch-up and subscription, position advances even for events with no registered handler (preventing future re-evaluation), and the catch-up-then-subscribe pattern eliminates gaps between historical replay and live events.
Three independent mechanisms collectively enforce exactly-once without distributed coordination
Depends on (SL): live-projection-idempotent-by-position, live-projection-position-advances-without-handler, catch-up-then-subscribe