Parallel 3-reviewer cleanup of the in-place compaction code. Findings applied:
- perf: in-place mode no longer pre-flushes current-turn messages. The flush
ran INSERTs that the immediately-following replace_messages(compressed)
DELETE+reinsert discarded -- pure wasted writes per compaction. The
current-turn tail survives via the compressor's compressed output
(protect_last_n), not the flush. Verified no data loss; rotation still
pre-flushes (its old session row is preserved, so the flush is real there).
- quality: hoist the two shared post-write steps (update_system_prompt +
_last_flushed_db_idx = 0) below the if/else -- they ran in both branches
against agent.session_id. Removes the easiest divergence bug.
- quality: compute the compaction-boundary locals (_old_sid, _is_boundary,
_boundary_parent) ONCE instead of recomputing locals().get('old_session_id')
and the "_old_sid or agent.session_id or ''" chain three times.
- quality: initialize compacted_in_place up front and assign
agent._last_compaction_in_place directly, dropping the fragile
locals().get('compacted_in_place') reflection.
- reuse: parse the in_place config flag with utils.is_truthy_value (the
project's canonical truthy coerce) instead of a hand-rolled
str().lower() in {...} (agent_init already imports from utils).
Dropped as false positives / out of scope: gateway getattr of agent internals
(established session_id pattern), dual result-dict carry (mirrors history_offset
etc.), stringly-typed "compression" (codebase-wide convention, no constant).
Behavior-preserving: 7 in-place tests (incl. 2 new flush-guard tests) + 26
rotation/boundary/persistence/command tests green; mutation check confirms the
durable-replace guard still binds (removing replace_messages fails the test);
ruff clean. Added test_in_place_skips_redundant_preflush /
test_rotation_still_preflushes to guard the perf change.
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