context (Haiku, Opus 5.5/High reviewer): 7/8 pass, 1 fail.
FAIL c3-stop-then-continue (medium, high confidence): manual /compact (src/session/compact.ts) summarized each chunk with no user request and no "Part i of n" marker; joined summary contradicted itself and invented files; model noticed conflict.
FIX (2026-10-30): session/compact.ts — split summaries give every part "Part i of n of one conversation…" plus the user's latest request (≤2000 units, context block stripped); chunk budget reserves the room. Test: c3 regression in tests/round10b-fixes.test.ts; engine-round5 E6 test now searches only inside <transcript>. 98 pass across 8 files; tsc clean.
HARNESS FIX: driver10b now sends messages left after a handoff/interrupt in the next session (j6's 6th message had been dropped).
Passes: c1 handoff machinery right (task too big for 60K + model re-read), c2 4 compactions ok, c4 chain keeps original request, c5 REPORT correct, c6 INDEX correct, c7 94.5% cache, j6 37/37.
Cache notes: c1 45%/c2 69%/c3 75%/c4 79% are by design — handoff writer & compaction summaries go through oneShot uncached; possible optimization: let the handoff writer reuse the session's cached prefix.
