RegenProgress:
| {
hiddenSize: number;
layers: number;
nextShard: number;
resumed: number;
tapLayers: readonly number[];
type: "start";
}
| { index: number; sequences: number; tokens: number; type: "shard" }
| {
done: number;
kept: number;
tokens: number;
total: number;
type: "topics";
}