Review feedback: the previous test called _mark_session_committed
directly, so it verified the guard's behavior but not the wiring that
sets it — a future break in the commit_memory_session -> same-id
compression-boundary path would not be caught.
Add a lifecycle regression that drives the real sequence: on_session_end
commits through the actual path, on_session_switch(same id,
reason="compression") crosses the boundary, sync_turn records a genuinely
new turn, and a second on_session_end must produce a second commit POST.
Without the fix it fails showing exactly one commit call, which is the
reported data loss: every turn after the first compression is dropped.
The rotation and /undo tests stay as scope guards.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
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