The rolling summary lives only in memory. A resumed session starts with an
empty one while the marker carrying every previously absorbed exchange is
still in the transcript. The first pass after a resume therefore built a
marker from a single exchange and superseded the marker holding the entire
history -- silently discarding everything micro-compaction had accumulated.
This was introduced by the supersede fix. Before it, markers piled up
wastefully, but nothing was ever lost.
Two changes, so a single failure cannot lose data:
Rehydrate. When the cursor is recovered by scanning the transcript -- the
resume path -- also recover the rolling summary from that marker, so the
next pass merges into the existing history instead of replacing it.
Extraction uses rfind for the heading because SUMMARY_PREFIX references the
heading text itself, so the first occurrence is inside the preamble.
Gate superseding. Earlier markers are dropped only when this pass's summary
is demonstrably cumulative, i.e. the rolling summary was non-empty going in.
If rehydration ever fails, the pass keeps both markers: wasteful, but the
history survives.
Tests cover the resume path, the failed-rehydration fallback, and the
round trip of a summary through a marker.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Michael Jordan
60781a0cc8