Function commit_pending_leave 

pub fn commit_pending_leave<EF, V, LF, D>(
    member: LiveMember<EF>,
    pending: PendingFinalization,
    detach_cell: DetachCell<D>,
    verified: VerifiedLeaveRequest<V, LF>,
    authority: PreparedLeaveAuthority,
    parameters: PendingLeaveCommitParameters,
) -> Result<LeaveCommit<EF, V, LF>, LeaveCommitError>

Positionally commits one pending binding terminal immediately before Left.

A separately drained terminal must first update LiveMember through its committed terminal and then use ordinary commit_leave.

Errors

Returns LeaveCommitError when the planner proof, pending state/cell, authority, or allocated sequence order is inconsistent.