Function run_projection 

pub async fn run_projection<P, B>(
    projector: P,
    backend: &B,
) -> Result<(), ProjectionError>
where
    P: Projector,
    P::Event: Event + Clone,
    P::Context: Default,
    P::Error: Debug,
    B: EventReader + CheckpointStore + ProjectorCoordinator,

Runs a projector against a backend that provides events, checkpoints, and coordination.

This is the primary entry point for running projections in EventCore. It orchestrates:

• Leadership acquisition via ProjectorCoordinator
• Event reading via EventReader
• Checkpoint management via CheckpointStore

Arguments

• projector - The projector implementation to run
• backend - A reference to a backend implementing EventReader, CheckpointStore, and ProjectorCoordinator

Returns

Returns when the projector completes processing all events (batch mode), is cancelled, or encounters a fatal error.

Example

// PostgreSQL provides all three traits
run_projection(my_projector, &postgres_store).await?;