Function merge_node_subscription_manifests 

pub fn merge_node_subscription_manifests(
    epoch: u64,
    checkpoint_id: u64,
    assignment_certificate: &CheckpointAssignmentFence,
    manifests: &[(&NodeSubscriptionManifest, &[u16])],
) -> Result<Vec<MergedSubscriptionCheckpoint>, SubscriptionContractError>

Merge one complete participant roster into canonical whole-cluster subscription cuts. Each manifest is paired with the exact owned-vnode roster from its enclosing checkpoint.

Errors

Returns an error for a missing participant manifest, certificate disagreement, duplicate or missing partition, wrong owner contribution, sequence gap, or malformed segment.