When cached session has no anchor_activity_scenes and the prefix reader
returns None (e.g. sidecar too large for prefix), the empty-scenes path
did not mark _scene_check_inconclusive = True. This meant an inactive
session with matching message counts would return False (cache fresh)
even though disk may have gained its first scene record.
Fix: the empty-scenes else-branch now sets _scene_check_inconclusive
when disk_meta_quick is None, matching the existing behavior in the
cached-scenes branch (line 3173). The code then falls through to the
full metadata comparison instead of serving a stale cache.
discussion_r3548650345
Konstantin M
12a60a88b4