apply_scene_close_summary fed detect_threads the chat-wide last-50
turns. When a chat has accumulated multiple scenes' worth of dialogue,
that bleeds prior-scene turns into the second close's classifier prompt
and risks mis-attributing threads (closing one that opened earlier,
re-opening one that already closed).
Add an optional ``since_event_id`` kwarg to ``_read_recent_dialogue``
that lower-bounds by event_log id, plus a ``_scene_opened_event_id``
helper that resolves the scene-open event for a given scene_id. Wire
both into the thread-detection call site so its scene_transcript
holds only the closing scene's turns. The per-POV summarizer keeps the
chat-wide approximation it had before — that's intentional.
Adds test_thread_detection_uses_scene_scoped_transcript.
Joseph Doherty
dae481eb92