Overview

load_changesets_range returns empty so replay does nothing.

Scope

• Load StateChangeSetExt for [from_order, to_order).
• Maintain ordering.
• Update report counts (changesets_processed, nodes_updated, stats).
• Propagate errors when range is missing.

Acceptance Criteria

• Replay applies non-empty changesets and mutates snapshot store.
• Progress tracking reflects real work.
• Tests cover a non-empty range.