`export_to_shards` asked `store.contains(file_id)` and skipped anything the
shard store had already heard of. So an image was exported exactly once, and
re-indexing it updated the catalog and nothing else — every other device kept
the first answer for ever.
That is not hypothetical. This library was re-indexed after the detection floors
changed and crops were added, going from 1,807 faces to 15,194; the shard store
still held the original 1,807, written before any of it. Nothing the re-index
produced could reach another device.
The shard's `indexed` table now carries the catalog's own `indexed_at`, and the
export compares against it. A re-indexed image goes again; an unchanged one
still costs nothing. Copied from the catalog rather than stamped when the shard
is written, because a shard-local write time advances even when nothing changed
and could not answer the question.
The column is nullable so a shard written before it still reads: absent means
"cannot vouch for it", which forces one re-export and then settles.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
dtourolleandClaude Opus 5
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