Rates Engine v0.5.0-rc.54

[v0.5.0-rc.54] — 2026-05-15

Fixed

• Backfill-coverage density now credits the live-ingest tail —
  caught-up sources reach (and stay at) ~100%. rc.53's
  cursor-first density only counted source='backfill' cursors, so
  every source showed a uniform ~281k-ledger shortfall (~96.8% for
  Soroban-era sources, 99.55% for sdex): the "head band" between
  the top of the backfill union and the live network tip. That band
  is not a data gap — the live ledgerstream cursor is covering
  it gap-free in real time — it was simply uncounted, so density
  could never reach 100% no matter how complete ingest was.
  extendWithLiveTail now unions [backfillTop, min(liveTop, tip)]
  on top of the merged backfill intervals. Honest by construction:
  a source with no backfill anchor (e.g. the un-audited
  defindex / soroswap-router, BackfillSafe=false) stays at
  0% — live-only decoding from the deploy ledger is not "we have
  its history"; the live contribution starts at backfillTop so an
  interior backfill hole is never falsely filled; and only the
  [backfillTop, tip] tail is asserted gap-free (the live path's
  contract + the archivecompleteness daemon, ADR-0017). A
  fully-caught-up source now reads ~100% and stays there as the tip
  advances.