The summing matrix and node ordering (from buildSummingMatrix).
Point forecasts per node id — every node must have an entry.
Optionaloptions: ReconcileOptionsReconciliation strategy and parameters.
Reconciled forecasts per node + projection matrix for diagnostics.
Reconcile base forecasts at all levels using the given strategy.
This is a pure function that operates on pre-computed base forecasts. It does not require a TimesFM model — use reconcileBaseForecasts when you already have forecasts at all nodes (e.g., from a separate forecasting step).