read_all_items was iterating all CRDT entries including stale duplicates
from earlier stage writes. A story written multiple times (backlog →
current → done) would appear in the output multiple times with different
stages, causing ghost entries in the pipeline status and backlog views.
Now iterates only the index (story_id → visible_index map) which
represents the latest-wins deduplicated view of each story.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>