Added tracing to the on-demand chunk fetching path (commit 8e1f3cb).
Implemented getTip for querying the current chain tip from remote storage (commit 57d17d9).
Explored a LightweightIterator approach for streaming chunks, then discarded it in favor of the current raw chunk iterator design which better fits the on-demand fetching model (commit 74a87f3).
Fixed a critical bug where chunksBetween always returned an empty list, preventing on-demand fetching from working at all (commit e32397a).
Preparing the codebase for extraction to a standalone repository (commit b606f77).
