- Add pagination-advance test: verifies since=checkpoint on second
iteration within a pass, and each pass re-seeds since from
peer.lastSyncedAt (not carried from prior pass).
- Eliminate four peer! non-null assertions by capturing the narrowed
value in activePeer after the guard.
- Tighten bodyObj type from Record<string, unknown> to a local
SyncRequestBody type alias.
- Drop the no-op federationRelayEnabled UPDATE in test beforeEach
(default is already 1 per baseline migration).
Jannis Braun
39c43032e8